Fix non-reserved macro names LIBCXXABI_NORETURN and LIBCXXABI_ARM_EHABI.

This patch adds the required leading underscore to those macros.

llvm-svn: 296567
diff --git a/libcxxabi/src/cxa_exception.hpp b/libcxxabi/src/cxa_exception.hpp
index 6e68f98..df550bf 100644
--- a/libcxxabi/src/cxa_exception.hpp
+++ b/libcxxabi/src/cxa_exception.hpp
@@ -27,7 +27,7 @@
 static const uint64_t get_vendor_and_language     = 0xFFFFFFFFFFFFFF00; // mask for CLNGC++
 
 struct __cxa_exception {
-#if defined(__LP64__) || LIBCXXABI_ARM_EHABI
+#if defined(__LP64__) || _LIBCXXABI_ARM_EHABI
     // This is a new field to support C++ 0x exception_ptr.
     // For binary compatibility it is at the start of this
     // struct which is prepended to the object thrown in
@@ -45,7 +45,7 @@
 
     int handlerCount;
 
-#if LIBCXXABI_ARM_EHABI
+#if _LIBCXXABI_ARM_EHABI
     __cxa_exception* nextPropagatingException;
     int propagationCount;
 #else
@@ -56,7 +56,7 @@
     void *adjustedPtr;
 #endif
 
-#if !defined(__LP64__) && !LIBCXXABI_ARM_EHABI
+#if !defined(__LP64__) && !_LIBCXXABI_ARM_EHABI
     // This is a new field to support C++ 0x exception_ptr.
     // For binary compatibility it is placed where the compiler
     // previously adding padded to 64-bit align unwindHeader.
@@ -70,7 +70,7 @@
 // The layout of this structure MUST match the layout of __cxa_exception, with
 // primaryException instead of referenceCount.
 struct __cxa_dependent_exception {
-#if defined(__LP64__) || LIBCXXABI_ARM_EHABI
+#if defined(__LP64__) || _LIBCXXABI_ARM_EHABI
     void* primaryException;
 #endif
 
@@ -83,7 +83,7 @@
 
     int handlerCount;
 
-#if LIBCXXABI_ARM_EHABI
+#if _LIBCXXABI_ARM_EHABI
     __cxa_exception* nextPropagatingException;
     int propagationCount;
 #else
@@ -94,7 +94,7 @@
     void *adjustedPtr;
 #endif
 
-#if !defined(__LP64__) && !LIBCXXABI_ARM_EHABI
+#if !defined(__LP64__) && !_LIBCXXABI_ARM_EHABI
     void* primaryException;
 #endif
 
@@ -104,7 +104,7 @@
 struct __cxa_eh_globals {
     __cxa_exception *   caughtExceptions;
     unsigned int        uncaughtExceptions;
-#if LIBCXXABI_ARM_EHABI
+#if _LIBCXXABI_ARM_EHABI
     __cxa_exception* propagatingExceptions;
 #endif
 };