Next batch of C++ to C comment style changes. Also improve and factor out endianness pre-processor code.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@78226 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ucmpti2.c b/lib/ucmpti2.c
index 826360c..ba32b84 100644
--- a/lib/ucmpti2.c
+++ b/lib/ucmpti2.c
@@ -1,23 +1,25 @@
-//===-- ucmpti2.c - Implement __ucmpti2 -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements __ucmpti2 for the compiler_rt library.
-//
-//===----------------------------------------------------------------------===//
+/* ===-- ucmpti2.c - Implement __ucmpti2 -----------------------------------===
+ *
+ *                     The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __ucmpti2 for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
 
 #if __x86_64
 
 #include "int_lib.h"
 
-// Returns:  if (a <  b) returns 0
-//           if (a == b) returns 1
-//           if (a >  b) returns 2
+/* Returns:  if (a <  b) returns 0
+ *           if (a == b) returns 1
+ *           if (a >  b) returns 2
+ */
 
 si_int
 __ucmpti2(tu_int a, tu_int b)