Profile runtime can generate an empty raw profile (when there is no function in
the shared library). This empty profile is treated as a text format profile. A
test format profile without the flag of "#IR" is thought to be a clang
generated profile. So in llvm profile merging, we will get a bogus warning of
"Merge IR generated profile with Clang generated profile."
The fix here is to skip the empty profile (when the buffer size is 0) for
profile merge.
Reviewers: vsk, davidxl
Differential Revision: http://reviews.llvm.org/D25687
llvm-svn: 284659
Rong Xu