[PATCH] [compiler-rt] Implement AddressSanitizer suppressions

[Kuba Brecka]

I'm also seeing another test failure for LSan suppressions when ASan is used together with LSan:

    FAIL: LeakSanitizer-AddressSanitizer :: TestCases/suppressions_file.cc (1 of 1)
    ...
    /tmp/llvm/projects/compiler-rt/test/lsan/TestCases/suppressions_file.cc:24:11: error: expected string not found in input
    // CHECK: Suppressions used:
              ^
    <stdin>:1:1: note: scanning from here
    Test alloc: 0x61700000fc80.
    ^
    <stdin>:9:73: note: possible intended match here
     #1 0x4cc625 in main /tmp/llvm/projects/compiler-rt/test/lsan/TestCases/suppressions_file.cc:20:13

It looks like that in ASan+LSan, we only have one "suppressions" flag, and once the SuppressionContext is initialized, it only reads the common_flags()->suppressions once. Should we support having suppressions work for both LSan and ASan at the same time? I.e. running

    ASAN_OPTIONS=suppressions=file1 LSAN_OPTIONS=suppressions=file2 ./a.out

In that case we should probably remove the "suppressions" flag from common_flags and have it separately in ASan, LSan, TSan.

Alexey, what do you think?

http://reviews.llvm.org/D6280