macro_rules! is like an item that defines a macro.  Other items don't have a
trailing semicolon, or use a paren-delimited body.

If there's an argument for matching the invocation syntax, e.g. parentheses for
an expr macro, then I think that applies more strongly to the *inner*
delimiters on the LHS, wrapping the individual argument patterns.

followed by a semicolon.

This allows code like `vec![1i, 2, 3].len();` to work.

This breaks code that uses macros as statements without putting
semicolons after them, such as:

    fn main() {
        ...
        assert!(a == b)
        assert!(c == d)
        println(...);
    }

It also breaks code that uses macros as items without semicolons:

    local_data_key!(foo)

    fn main() {
        println("hello world")
    }

Add semicolons to fix this code. Those two examples can be fixed as
follows:

    fn main() {
        ...
        assert!(a == b);
        assert!(c == d);
        println(...);
    }

    local_data_key!(foo);

    fn main() {
        println("hello world")
    }

RFC #378.

Closes #18635.

[breaking-change]

This makes it easier to experiment with improved quasiquoting as an ordinary
plugin library.

The list of quote macros in feature_gate.rs was already out of sync;
this commit also prevents that problem in the future.

Specifically, dissallow setting the number base for every type of float
literal, not only those that contain the decimal point. This is in line with
the description in the manual.

If the main closure failed, then the `exit_code` variable would still be `None`,
and the `unwrap()` was failing (triggering a process abort). This changes the
`unwrap()` to an `unwrap_or()` in order to prevent process abort and detect when
the native task failed.

If there is a lot of data in thread-local storage some implementations
of pthreads (e.g. glibc) fail if you don't request a stack large enough
-- by adjusting for the minimum size we guarantee that our stacks are
always large enough. Issue #6233.

Closes #7246
Closes #7573

This is required by the check-fast target because each test is slurped up into a
submodule.

 - also removed redundant assignment to is_mutbl
 - updated copyright

Remove disr_val from ast::variant_ and always use ty::variant_info
when the value is needed.  Move what was done during parsing into
other passes, primary typeck.rs.  This move also correctly type checks
the disr. value expression; thus, fixing rustc --pretty=typed when
disr. values are used.