[esan] Add __esan_report for mid-run data

Summary:
Adds a new public interface routine __esan_report() which can be used to
request profiling results prior to abnormal termination (e.g., for a server
process killed by its parent where the normal exit does not allow for
normal result reporting).

Implements this for the working-set tool.  The cache frag tool is left
unimplemented as it requires missing iteration capabilities.

Adds a new test.

Reviewers: aizatsky

Subscribers: vitalybuka, zhaoqin, kcc, eugenis, llvm-commits, kubabrecka

Differential Revision: http://reviews.llvm.org/D22098

llvm-svn: 274964
diff --git a/compiler-rt/lib/esan/cache_frag.cpp b/compiler-rt/lib/esan/cache_frag.cpp
index 343abfc..a3e612d 100644
--- a/compiler-rt/lib/esan/cache_frag.cpp
+++ b/compiler-rt/lib/esan/cache_frag.cpp
@@ -199,4 +199,10 @@
   return 0;
 }
 
+void reportCacheFrag() {
+  VPrintf(2, "in esan::%s\n", __FUNCTION__);
+  // FIXME: Not yet implemented.  We need to iterate over all of the
+  // compilation unit data.
+}
+
 } // namespace __esan