[PATCH] [sanitizer] Fix kThreadDescriptorSize for glibc <= 2.11.

[Kostya Serebryany]

  LGTM


================
Comment at: lib/sanitizer_common/sanitizer_linux_libcdep.cc:198
@@ -197,1 +197,3 @@
 // sizeof(struct thread) from glibc.
+// There has been a report of this being different on glibc 2.11. We don't know
+// when this change happened, so 2.12 is a conservative estimate.
----------------
Well, you can figures this out with some effort :) 
But ok for now. 


http://llvm-reviews.chandlerc.com/D907

BRANCH
  fix/sanitizer/descr_size

ARCANIST PROJECT
  compiler-rt