Fix type definitions of size_t and wchar_t in the built-in stddef.h

Author: robertoraggi

src/lib/cxx/include/stddef.h

@@ -10,16 +10,17 @@
 
 #ifdef __need_ptrdiff_t
 #undef __need_ptrdiff_t
-typedef long int ptrdiff_t;
+typedef __PTRDIFF_TYPE__ ptrdiff_t;
 #endif /* __need_ptrdiff_t */
 
 #ifdef __need_size_t
 #undef __need_size_t
-typedef long unsigned int size_t;
+typedef __SIZE_TYPE__ size_t;
 #endif /* __need_size_t */
 
 #ifdef __need_wchar_t
 #undef __need_wchar_t
+typedef __WCHAR_TYPE__ wchar_t;
 #endif /* __need_wchar_t */
 
 #ifdef __need_NULL

tests/unit_tests/parser/c_stdlib.c

@@ -1,4 +1,4 @@
-// RUN: %cxx -toolchain wasm32 -verify %s
+// RUN: %cxx -toolchain wasm32 -verify -fcheck %s
 
 #include <assert.h>
 #include <complex.h>