My local build of delve which apparently pulls in the master branch starting breaking. This is the culprit.

Error:
```
#9 75.27 # github.com/go-delve/delve/service/dap
#9 75.27 /usr/src/github.com/go-delve/delve/service/dap/server.go:107:1: syntax error: unexpected <<, expecting field name or embedded type
#9 75.27 /usr/src/github.com/go-delve/delve/service/dap/server.go:110:1: syntax error: unexpected ==, expecting field name or embedded type
#9 75.27 /usr/src/github.com/go-delve/delve/service/dap/server.go:113:1: syntax error: unexpected >>, expecting field name or embedded type
```

A RequestManualStop received while the target program is stopped can
induce a crash when the target is restarted.
This is caused by the phantom breakpoint detection that was introduced
in PR #2179 / commit e69d536e.
Instead of always interpreting an unexplained SIGTRAP as a phantom
breakpoint memorize all possible unreported breakpoint hits and only
act on it when the thread hasn't moved from one.

Also clarifies the behavior of the halt command when it is received
while the target is stopped or in the process of stopping.

Handle the signaled status for the thread leader like we handle the
exited status, by returning ErrProcessExited and recording the killer
signal  in it.
Prior to this commit we would find out about the death of the thread
later in the loop, the condition would still be reported as
ErrProcessExited, but without recording the signal number anywhere.

Also fixes a bug in TestAttachStopOnEntry where the test would
inadvertently cause a SIGPIPE to be sent to the target process, making
it terminate early.

* service/dap: implement exception info

* remove adding additional thread

* Fix tests

* add exceptionInfo tests

* update comments

* map paths to client paths

* remove launch.json

* remove change to ConvertEvalScope

* correct name of supportsExceptionInfoRequest

* Add TODO for deleting output event

* Print Stack header to buffer

* Try to move resolving exception info to onExceptionInfoRequest

* save the error and return if it is the current thread

* rename thread to g

* findgoroutine returns goroutine

* clean up findgoroutine

* log errors

* remove output event

* fix grammar

* service/dap: warn users of debugging optimized functions

* Add test for optimized scopes

* service/dap: warn users of debugging optimized functions

* rename functionscope

* update warning message

* service/dap: support setting breakpoints while running

* Review comments, faster test

* Fix comments

* Address review comments

* Do not continue automatically

* Add TODO to resume exeuction

* Handle async test messages in either order
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

Accept the empty response in case the threads request arrived after the program
terminated

Messages don't look good with %q.

Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

* service/dap: add type information to dap variables

* add comment explaining map type choice

* rename to setClientCapabilities

* respond to review

* update TypeString definition

Adds the low-level support for watchpoints (aka data breakpoints) to
the native linux/amd64 backend.

Does not add user interface or functioning support for watchpoints
on stack variables.

Updates #279

Bintray is shutting down and the URL we used to install mingw is no
longer available. Use chocolatey instead.

daptest has type assertion functions that panic
if the read response/event message is not
the expected type. This is not only against the
recommended style guideline (Don't Panic, Useful
Test Failures, ...), but also it prevents from
quickly diagnosing test failures occurred in remote
CIs.

This PR changes the type assertion to the two
return value type assertion, and t.Fatal with details
if the type is not expected.
service/dap/daptest/main.go is a program that auto
generates those assertion functions in resp.go.

Run `go generate` from the service/dap directory
to update resp.go.

The client can specify certain configurations in the initialize request.
For example, pathFormat determines the pathFormat. We do not currently
support configuring pathFormat, linesStartAt1, or columnsStartAt1, so
we report an error if the client attempts to set these to an
unsupported value.

Changes the expression evaluation code so that register names, when not
shadowed by local or global variables, will evaluate to the current
value of the corresponding CPU register.

This allows a greater flexibility with displaying CPU registers than is
possible with using the ListRegisters API call. Also it allows
debuggers users to view register values even if the frontend they are
using does not implement a register view.

* service/dap: auto-loading for fully missing pointers, structs, maps, slices and arrays

* Add call test

* Add TODO
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

* service/dap: refine teardown logic

* Address review comments + add missing lock/unlock

* Narrow lock scope

* Update comments only

* Remove redundan temp var from stopNoDebugProcess

* Clarify comment

* service/dap: support running requests asynchronously

* Respond to review comments

* Remove debugging printf

* Refine locking. Add call TODO. Use -1 for running thread id.

* Fix TestAttachStopOnEntry: it can terminate on halt

* Respond to review comments

* Recover panics in async requests handling

* defer releasing asyncSetupDone, so it happens on panic
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

Add documentation on how to pass arguments to the program generated by
`dlv test`.

Fixes #2458

Check for errors, log them and return early, do not try to allocate
large chunks of memory that we can never possibly read from the file.

Fixes #2449

* go.mod: update google/go-dap to 0.5.0

* Go mod tidy
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

* proc: Slightly better version check for gdb server on newer macOS

* Adjusted version to be >= 1200 and <= 1205

The documentation mentions flags that do not exist. Replace them with
the existing, --log-dest flag.

Moves the implementation of Registers.Get out of the backends and into
proc where it can be implemented only once per architecture.

* examinememory: evaluate addr as expression

This makes it easy to read memory locations at an offset of a known
address, e.g.:

x 0xc000046800 + 32

* use feedback from @aarzilli

- expression mode is now enabled via -x flag
- support "-x var", "-x &var" in addition to "-x <addr expr>"
- some refactoring

* add test cases

* deal with double spaces

* update docs

* add new failing test

* fix docs

* simplify implementation, update test & docs

* Fix docs

* service/dap: add go build stderr to error response

* service/dap: add go build stderr to error response

* Skip message check for build errors

* test for flag provided message

Due to variable shadowing the SwitchGoroutine command never failed.

There seems to be a problem where debugserver will leave a zombie
process instead of detaching correctly, we are sending the right
commands, it doesn't seem to be a problem with Delve.

* service/dap: refine teardown logic

* Address review comments + add missing lock/unlock

* Narrow lock scope

* Update comments only

* Remove redundan temp var from stopNoDebugProcess

* Clarify comment

* Set debugger to nil after detach to prevent dup teardown in Stop()
Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

Rename the launch configuration for specifying the working directory.

* service/dap: annotate shadowed variable names in variables request

In order to distinguish variables that are shadowed, this change
updates the names from 'name' to '(name)'. This is the same syntax
used in the terminal package.

* remove unnecessary comment

* Add todo for evaluate name

* Check the evaluateName result is the unshadowed var

* service/rpcommon: resolve race between Detach and shutdown

Detach will close DisconnectChan causing the server to initiate
shutdown, there is a race between Detach writing its response to the
client and the shutdown terminating the server process.
If Detach loses the race the response to the Detach request is never
sent to the client and the client will report an EOF error instead.

This change delays the start of the shutdown process until after Detach
has written its response.

Fixes an occasional failure of TestContinue.

* service/rpccommon: ignore listener error when shutting down

Ignore the closed listener error when the server is being shut down in
response to a SIGINT signal.

Fixes #1633

* service/dap: add substitutePath configuration

Similar to substitute-path configuration in the dlv cli, substitutePath
in dap allows users to specify path mappings that are applied to the
source files in stacktrace and breakpoint requests.

Updates #2203

* service/dap: refactor the startup of the fixture for attach

Add a helper function for starting up a process to attach to.

* service/dap: update substitute path tests for windows

* service/dap: remove lines that should have been removed in merge

* respond to comments on pr

* move logging to helper functions

* make test comments more clear

* Add comments about absolute paths

* fix log messages

* clarify test comments

* remove comment about absolute paths

Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>

We have some places where we use proc.ErrProcessExited and some places
that use &proc.ErrProcessExited, resulting in checks for process exited
errors occasionally failing on some architectures.
Uniform use of ErrProcessExited to the non-pointer version.

Fixes intermittent failure of TestStepOutPreservesGoroutine.

Co-authored-by: NPolina Sokolova <polinasok@users.noreply.github.com>