More MSVC warning fixes:
1. DUPMAX is defined in regcomp.c, no need to redefine it in regutils.
2. MSVC doesn't like snprintf, use _snprintf instead.

llvm-svn: 81114
diff --git a/llvm/lib/Support/regerror.c b/llvm/lib/Support/regerror.c
index 88d33b8..1d67c9a 100644
--- a/llvm/lib/Support/regerror.c
+++ b/llvm/lib/Support/regerror.c
@@ -45,6 +45,10 @@
 
 #include "regutils.h"
 
+#ifdef _MSC_VER
+#define snprintf _snprintf
+#endif
+
 static const char *regatoi(const llvm_regex_t *, char *, int);
 
 static struct rerr {