When compression is applied by default running the DWZ tool on the
resulting binary will crash.

The actual default compression code will look and see if compression
makes any difference and if so replace the normal `.debug_*` section
with `.zdebug_*`. This is why it may not have been hit before. On one of
my workstations I build with 1.12rc1 and no compression happens, but on
a Fedora VM I build and the binary results in compressed DWARF sections.

Adding this flag will make this test more consistent overall.

Fixes #1471

This file should be located elsewhere (on the OSX host, I believe) and
as such does not beed to be checked in here.

Fixes #1460

FindGoroutine can be slow when there are many goroutines running. This
can not be fixed in the general case, however:

1. Instead of getting the entire list of goroutines at once just get a
   few at a time and return as soon as we find the one we want.

2. Since FindGoroutine is mostly called by ConvertEvalScope and users
   are more likely to request informations about a goroutine running on a
   thread, look within the threads first.

The allg cache was corrupted when the count parameter was actually
reached.

Fix the bug and add a test for this.

The repository is being switched from the personal account
github.com/derekparker/delve to the organization account
github.com/go-delve/delve. This patch updates imports and docs, while
preserving things which should not be changed such as my name in the
CHANGELOG and in TODO comments.

Some build environments (such as when building RPMs) enjoy symlinking
things. This unfortunately causes our tests to fail as we record the
path of fixtures and use that when looking up file:line information.
However, the debug info in the binary records the original file
location, not the location of the symlink.

When casting an integer into a struct pointer we make a fake pointer
variable that doesn't have an address, maybeDereference and
structMember should still work on this kind of Variable.

Fixes #1432

PTRACE_GETREGSET was added in Linux 2.6.34, running this request in an
older kernel will report EIO, as documented on the manpage.

Fixes #1197

The size of the TLS memory arena needs to be aligned to pointer sized
boundaries on 86x64 architectures, otherwise some programs using cgo
will not have the correct offset for the g struct.

No tests because reproducing this problem depends on behavior of the
GNU ld linker caused by unclear influences.

Fixes #1428.

Goroutine id == 0 is special (there can be many goroutines with id 0).
If the caller of FindGoroutine asks for gid==0 and current thread is
running a goroutine 0 (i.e. either no goroutine or a special
goroutine) return whatever goroutine is running on the current thread.

Updates #1428

The fix in 7f53117e for Issue #1416 had a bug, fix it and add a test.

Fixes #1419

Minidumps are the windows equivalent of unix core files.
This commit updates pkg/proc/core so that it can open and read windows
minidumps.

Updates #794

Move windows register handling code to winutil package in preparation
for using it in proc/core to read minidump files.

If a function can be inlined it will appear as two entries in
debug_info. A DW_TAG_subprogram entry with DW_AT_inlined = true (that
will be used as the abstract origin) and a second DW_TAG_subprogram
entry with an abstract origin.
To retrieve the name of this second entry we must load its abstract
origin.

If proc.Step encounters a CALL instruction that points to an address
that isn't associated with any function it should still follow the
CALL.

The circumstances creating this problem do not normally occur, it was
encountered in the process of fixing a bug created by Go1.12.

It was never true that return variables were in the inverse order.
Instead in Go1.11 return variables are saved in debug_info in an
arbitrary order and inverting them just happened to work for this
specific example.

This bug was fixed in Go 1.12, regardless we should attempt to
rearrange return variables anyway.

When a location expression requests a register check that we have as
many bytes in the register as requested and if we don't report the
error.

Updates #1416

Instead of unconditionally returning all present goroutines,
GoroutinesInfo now allows specifying a range (start and count). In
addition to the array of goroutines and the error, it now also returns
the next goroutine to be processed, to be used as 'start' argument on
the next call, or 0 if all present goroutines have already been
processed.

This way clients can avoid eating large amounts of RAM while debugging
core dumps and processes with a exceptionally high amount of goroutines.

Fixes #1403

This patch is a slight refactor to share more code used for genericprocess initialization. There will always be OS/backend specificinitialization, but as much as can be shared should be to preventduplicating of any logic (setting internal breakpoints, loading bininfo,etc).

Users can create sparse maps in two ways, either by:
a) adding lots of entries to a map and then deleting most of them, or
b) using the make(mapType, N) expression with a very large N

When this happens reading the resulting map will be very slow
because loadMap needs to scan many buckets for each entry it finds.

Technically this is not a bug, the user just created a map that's
very sparse and therefore very slow to read. However it's very
annoying to have the debugger hang for several seconds when trying
to read the local variables just because one of them (which you
might not even be interested into) happens to be a very sparse map.

There is an easy mitigation to this problem: not reading any
additional buckets once we know that we have already read all
entries of the map, or as many entries as we need to fulfill the
MaxArrayValues parameter.

Unfortunately this is mostly useless, a VLSM (Very Large Sparse Map)
with a single entry will still be slow to access, because the single
entry in the map could easily end up in the last bucket.

The obvious solution to this problem is to set a limit to the
number of buckets we read when loading a map. However there is no
good way to set this limit.
If we hardcode it there will be no way to print maps that are beyond
whatever limit we pick.
We could let users (or clients) specify it but the meaning of such
knob would be arcane and they would have no way of picking a good
value (because there is no objectively good value for it).

The solution used in this commit is to set an arbirtray limit on
the number of buckets we read but only when loadMap is invoked
through API calls ListLocalVars and ListFunctionArgs. In this way
`ListLocalVars` and `ListFunctionArgs` (which are often invoked
automatically by GUI clients) remain fast even in presence of a
VLSM, but the contents of the VLSM can still be inspected using
`EvalVariable`.

Adds a config file option to allow specifying a list of directories to
search in when looking for seperate external debug info files.

Fixes #1353

Make code in core.go OS and architecture agnostic in preparation for
adding Windows minidump support.

The linux version of proc/native and proc/core contained largely
overlapping implementations of the register handling code, deduplicate
it by moving it into proc/linutil.

This patch allows the `trace` CLI subcommand to display return values of
a function. Additionally, it will also display information on where the
function exited, which could also be helpful in determining the path
taken during function execution.

Fixes #388

Some libraries (for example steam_api64.dll) will send this exception
code to set the thread name on Microsoft VisualC.
In theory it should be fine to send the exception back to the target,
which is responsible for setting a handler for it, in practice in some
cases (steam_api64.dll) this will crash the program. So we'll mask it
instead.

Fixes #1383

ContinueOnce didn't detect the way RR signals that it has reached the
start of the process and would never finish.

Fixes #1376

Continue did not resume execution after a call to CallFunction if the
point where the process was stopped, before the call CallFunction, was
a breakpoint.

Fixes #1374

Add ability to evaluate variables on the scope of a deferred call's
argument frame.

Fix escape checking in function calls  and add a flag to disable it.

Extend `string()`
1.convert `byte/rune array`(not only `slice`) to string.
2.convert string to string(itself), just like `string(str)` in go language.

Support for position independent executables (PIE) on the native linux
backend, the gdbserver backend on linux and the core backend.
Also implemented in the windows native backend, but it can't be tested
because go doesn't support PIE on windows yet.

On macOS 10.14 Apple changed the command line tools so that system
headers now need to be manually installed.

Instead of adding one extra install step to the install procedure add a
build tag to allow compilation of delve without the native backend on
macOS. By default (i.e. when using `go get`) this is how delve will be
compiled on macOS, the make script is changed to enable compiling the
native backend if the required dependencies have been installed.

Insure that both configuration still build correctly on Travis CI and
change the documentation to describe how to compile the native backend
and that it isn't normally needed.

Fixes #1359

With this syntax users do not need to type the concrete type of an
interface variable to access its contents. This also sidesteps the
problem where the serialization of a type by go/printer is different
from the one used for debug_info type names.

Updates #1328

Use IsInternal and IsUser of Breakpoint, not duplicate code

Go allows converting a single integer value to string, resulting in a
string containing a single unicode rune with the same code as the value
of the integer.
Allow the same conversion to happen.

Fixes #1322

Instead of failing on the first goroutine we can't read save the error
message and keep going.

Fixes a bug reported on the mailing list:
https://groups.google.com/d/msgid/delve-dev/3b3bfaa3-83d5-4676-b974-1fec40e5bf53%40googlegroups.com?utm_medium=email&utm_source=footer