PGO: Change runtime prefix from pgo to profile

These functions are in the profile runtime.  PGO comes later.

Unfortunately, there's only room for 16 characters in a Darwin section,
so use __llvm_prf_ instead of __llvm_profile_ for section names.

<rdar://problem/15943240>

llvm-svn: 204390
diff --git a/clang/test/Profile/cxx-throws.cpp b/clang/test/Profile/cxx-throws.cpp
index c243947..cdcf53a 100644
--- a/clang/test/Profile/cxx-throws.cpp
+++ b/clang/test/Profile/cxx-throws.cpp
@@ -9,8 +9,8 @@
 // RUN: %clang %s -o - -emit-llvm -S -fprofile-instr-use=%S/Inputs/cxx-throws.profdata -target %itanium_abi_triple | FileCheck -check-prefix=PGOUSE %s
 // RUN: %clang %s -o - -emit-llvm -S -fprofile-instr-use=%S/Inputs/cxx-throws.profdata -target %itanium_abi_triple | FileCheck -check-prefix=PGOUSE-EXC %s
 
-// PGOGEN: @[[THC:__llvm_pgo_counters__Z6throwsv]] = global [9 x i64] zeroinitializer
-// PGOGEN-EXC: @[[THC:__llvm_pgo_counters__Z6throwsv]] = global [9 x i64] zeroinitializer
+// PGOGEN: @[[THC:__llvm_profile_counters__Z6throwsv]] = global [9 x i64] zeroinitializer
+// PGOGEN-EXC: @[[THC:__llvm_profile_counters__Z6throwsv]] = global [9 x i64] zeroinitializer
 
 // PGOGEN-LABEL: @_Z6throwsv()
 // PGOUSE-LABEL: @_Z6throwsv()