[Sanitizer] Fix report_path functionality:
Summary:
- Make sure mmap() is never called inside RawWrite function.
- Wrap a bunch of standalone globals in a ReportFile object.
- Make sure accesses to these globals are thread-safe.
- Fix report_path functionality on Windows, where
__sanitizer_set_report_path() would break program.
I've started this yak shaving in order to make
"CommonFlags::mmap_limit_mb" immutable. Currently we drop this flag
to zero before printing an error message.
Test Plan: regression test suite
Reviewers: kcc, glider
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6595
llvm-svn: 224031