Add cwchar/wchar.h as stubs

Author: lcartey

cpp/common/test/includes/standard-library/cwchar

@@ -0,0 +1,18 @@
+#pragma once
+#ifndef _GHLIBCPP_CWCHAR
+#define _GHLIBCPP_CWCHAR
+#include "wchar.h"
+
+namespace std {
+using ::fgetwc;
+using ::fputwc;
+using ::wcstod;
+using ::wcstof;
+using ::wcstol;
+using ::wcstold;
+using ::wcstoll;
+using ::wcstoul;
+using ::wcstoull;
+} // namespace std
+
+#endif // _GHLIBCPP_CWCHAR

cpp/common/test/includes/standard-library/wchar.h

@@ -0,0 +1,19 @@
+#ifndef _GHLIBCPP_WCHAR
+#define _GHLIBCPP_WCHAR
+
+#include "stddef.h"
+
+// Wide character I/O functions
+wchar_t fgetwc(void *stream);
+wchar_t fputwc(wchar_t wc, void *stream);
+
+// Wide character string conversion functions
+long wcstol(const wchar_t *str, wchar_t **endptr, int base);
+long long wcstoll(const wchar_t *str, wchar_t **endptr, int base);
+unsigned long wcstoul(const wchar_t *str, wchar_t **endptr, int base);
+unsigned long long wcstoull(const wchar_t *str, wchar_t **endptr, int base);
+double wcstod(const wchar_t *str, wchar_t **endptr);
+float wcstof(const wchar_t *str, wchar_t **endptr);
+long double wcstold(const wchar_t *str, wchar_t **endptr);
+
+#endif // _GHLIBCPP_WCHAR