More windows port work by Ruben Van Boxem

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@142732 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/cstring b/include/cstring
index 1a23055..dd49d80 100644
--- a/include/cstring
+++ b/include/cstring
@@ -93,7 +93,8 @@
 
 using ::strstr;
 
-#ifndef __GLIBC__ // GNU libc and its derivates already have the correct prototype in <string.h> #ifdef __cplusplus
+// MSVC, GNU libc and its derivates already have the correct prototype in <string.h> #ifdef __cplusplus
+#if !defined(__GLIBC__) && !defined(_MSC_VER)
 inline _LIBCPP_INLINE_VISIBILITY       char* strchr(      char* __s, int __c) {return ::strchr(__s, __c);}
 inline _LIBCPP_INLINE_VISIBILITY       char* strpbrk(      char* __s1, const char* __s2) {return ::strpbrk(__s1, __s2);}
 inline _LIBCPP_INLINE_VISIBILITY       char* strrchr(      char* __s, int __c) {return ::strrchr(__s, __c);}