Improve error reporting for invalid var-decls.

We now interpret any statement of the form `Type identifier...` as a
var-declaration and report errors as such. Previously, if a var-decl
statement generated an error during parse, we'd report errors as if it
were an expression-statement, which meant that slightly-invalid code
could return out-of-context, misleading errors.

Bug: skia:11287
Change-Id: I2c6cf2984760eb34593c80cb30f8c4e007d42027
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/370036
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
5 files changed