Typo fix SIBABRT -> SIGABRT.

Based on a patch by Henry Wong!

llvm-svn: 322902
diff --git a/llvm/lib/Support/Windows/Signals.inc b/llvm/lib/Support/Windows/Signals.inc
index 21dd2dd..23fc72e 100644
--- a/llvm/lib/Support/Windows/Signals.inc
+++ b/llvm/lib/Support/Windows/Signals.inc
@@ -503,7 +503,7 @@
   _set_error_mode(_OUT_TO_STDERR);
 }
 
-/// PrintStackTraceOnErrorSignal - When an error signal (such as SIBABRT or
+/// PrintStackTraceOnErrorSignal - When an error signal (such as SIGABRT or
 /// SIGSEGV) is delivered to the process, print a stack trace and then exit.
 void sys::PrintStackTraceOnErrorSignal(StringRef Argv0,
                                        bool DisableCrashReporting) {