PGO: Declare zero-argument C functions as foo(void)

It turns out this is C code.  Specify foo(void).

<rdar://problem/15943240>

llvm-svn: 204396
diff --git a/compiler-rt/lib/profile/InstrProfilingExtras.c b/compiler-rt/lib/profile/InstrProfilingExtras.c
index 9089004..87006e8 100644
--- a/compiler-rt/lib/profile/InstrProfilingExtras.c
+++ b/compiler-rt/lib/profile/InstrProfilingExtras.c
@@ -29,7 +29,7 @@
   CurrentFilename = Filename;
 }
 
-void __llvm_profile_write_file() {
+void __llvm_profile_write_file(void) {
   const char *Filename = CurrentFilename;
 
 #define UPDATE_FILENAME(NextFilename) \
@@ -41,7 +41,7 @@
   __llvm_profile_write_file_with_name(Filename);
 }
 
-void __llvm_profile_register_write_file_atexit() {
+void __llvm_profile_register_write_file_atexit(void) {
   static int HasBeenRegistered = 0;
 
   if (!HasBeenRegistered) {