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: 204391
diff --git a/compiler-rt/lib/profile/InstrProfilingExtras.c b/compiler-rt/lib/profile/InstrProfilingExtras.c
index 745bcb0..9089004 100644
--- a/compiler-rt/lib/profile/InstrProfilingExtras.c
+++ b/compiler-rt/lib/profile/InstrProfilingExtras.c
@@ -9,27 +9,27 @@
 
 #include "InstrProfiling.h"
 
-static void __llvm_pgo_write_file_with_name(const char *OutputName) {
+static void __llvm_profile_write_file_with_name(const char *OutputName) {
   FILE *OutputFile;
   if (!OutputName || !OutputName[0])
     return;
   OutputFile = fopen(OutputName, "w");
   if (!OutputFile) return;
 
-  /* TODO: mmap file to buffer of size __llvm_pgo_get_size_for_buffer() and
+  /* TODO: mmap file to buffer of size __llvm_profile_get_size_for_buffer() and
    * pass the buffer in, instead of the file.
    */
-  __llvm_pgo_write_buffer(OutputFile);
+  __llvm_profile_write_buffer(OutputFile);
 
   fclose(OutputFile);
 }
 
 static const char *CurrentFilename = NULL;
-void __llvm_pgo_set_filename(const char *Filename) {
+void __llvm_profile_set_filename(const char *Filename) {
   CurrentFilename = Filename;
 }
 
-void __llvm_pgo_write_file() {
+void __llvm_profile_write_file() {
   const char *Filename = CurrentFilename;
 
 #define UPDATE_FILENAME(NextFilename) \
@@ -38,14 +38,14 @@
   UPDATE_FILENAME("default.profdata");
 #undef UPDATE_FILENAME
 
-  __llvm_pgo_write_file_with_name(Filename);
+  __llvm_profile_write_file_with_name(Filename);
 }
 
-void __llvm_pgo_register_write_file_atexit() {
+void __llvm_profile_register_write_file_atexit() {
   static int HasBeenRegistered = 0;
 
   if (!HasBeenRegistered) {
     HasBeenRegistered = 1;
-    atexit(__llvm_pgo_write_file);
+    atexit(__llvm_profile_write_file);
   }
 }