Fix UINT64_C/INT64_C macros under wasm64 (#26688)

Musl was assuming that 64-bit targets using `long` for int64_t but
WebAssembly is a little different to other plaforms in that we use `long
long` for int64_t for both 32-bit and 64-bit targets. See
http://reviews.llvm.org/D12861.

Fixes: llvm/llvm-project#192236

Author: sbc100

system/lib/libc/musl/include/stdint.h

@@ -119,7 +119,13 @@ typedef uint64_t uint_least64_t;
 #define UINT16_C(c) c
 #define UINT32_C(c) c ## U
 
-#if UINTPTR_MAX == UINT64_MAX
+// XXX EMSCRIPTEN: Use the clang-builtin macros here when available.
+#ifdef __UINT64_C
+#define INT64_C __INT64_C
+#define UINT64_C __UINT64_C
+#define INTMAX_C __INTMAX_C
+#define UINTMAX_C __UINTMAX_C
+#elif UINTPTR_MAX == UINT64_MAX
 #define INT64_C(c) c ## L
 #define UINT64_C(c) c ## UL
 #define INTMAX_C(c)  c ## L

test/other/test_stdint_limits.64.out

@@ -10,6 +10,10 @@ PTRDIFF_MIN: -9223372036854775808
 PTRDIFF_MAX: 9223372036854775807
 INTPTR_MIN: -9223372036854775808
 INTPTR_MAX: 9223372036854775807
+WCHAR_MIN: -2147483648
+WCHAR_MAX: 2147483647
+WINT_MIN: 0
+WINT_MAX: 4294967295
 UINTPTR_MAX: 18446744073709551615
 SIZE_MAX: 18446744073709551615
 SSIZE_MAX: 9223372036854775807
@@ -25,3 +29,11 @@ UINT8_MAX: 255
 UINT16_MAX: 65535
 UINT32_MAX: 4294967295
 UINT64_MAX: 18446744073709551615
+INT8_C: (d) 42
+INT16_C: (d) 42
+INT32_C: (d) 42
+INT64_C: (lld) 42
+INTU8_C: (u) 42
+INTU16_C: (u) 42
+INTU32_C: (u) 42
+INTU64_C: (llu) 42

test/other/test_stdint_limits.c

@@ -1,7 +1,8 @@
+#include <assert.h>
+#include <inttypes.h>
 #include <limits.h>
-#include <stdio.h>
 #include <stdint.h>
-#include <inttypes.h>
+#include <stdio.h>
 
 int main () {
   printf("INT_MIN: %d\n", INT_MIN);
@@ -22,6 +23,12 @@ int main () {
   printf("INTPTR_MIN: %ld\n", INTPTR_MIN);
   printf("INTPTR_MAX: %ld\n", INTPTR_MAX);
 
+  printf("WCHAR_MIN: %d\n", WCHAR_MIN);
+  printf("WCHAR_MAX: %d\n", WCHAR_MAX);
+
+  printf("WINT_MIN: %u\n", WINT_MIN);
+  printf("WINT_MAX: %u\n", WINT_MAX);
+
   printf("UINTPTR_MAX: %lu\n", UINTPTR_MAX);
 
   printf("SIZE_MAX: %zu\n", SIZE_MAX);
@@ -42,5 +49,16 @@ int main () {
   printf("UINT16_MAX: %" PRIu16 "\n", UINT16_MAX);
   printf("UINT32_MAX: %" PRIu32 "\n", UINT32_MAX);
   printf("UINT64_MAX: %" PRIu64 "\n", UINT64_MAX);
+
+  // Test macros for creating integer constants
+  printf("INT8_C: (" PRId8 ") %" PRId8 "\n", INT8_C(42));
+  printf("INT16_C: (" PRId16 ") %" PRId16 "\n", INT16_C(42));
+  printf("INT32_C: (" PRId32 ") %" PRId32 "\n", INT32_C(42));
+  printf("INT64_C: (" PRId64 ") %" PRId64 "\n", INT64_C(42));
+
+  printf("INTU8_C: (" PRIu8 ") %" PRIu8 "\n", UINT8_C(42));
+  printf("INTU16_C: (" PRIu16 ") %" PRIu16 "\n", UINT16_C(42));
+  printf("INTU32_C: (" PRIu32 ") %" PRIu32 "\n", UINT32_C(42));
+  printf("INTU64_C: (" PRIu64 ") %" PRIu64 "\n", UINT64_C(42));
   return 0;
 }

test/other/test_stdint_limits.out

@@ -10,6 +10,10 @@ PTRDIFF_MIN: -2147483648
 PTRDIFF_MAX: 2147483647
 INTPTR_MIN: -2147483648
 INTPTR_MAX: 2147483647
+WCHAR_MIN: -2147483648
+WCHAR_MAX: 2147483647
+WINT_MIN: 0
+WINT_MAX: 4294967295
 UINTPTR_MAX: 4294967295
 SIZE_MAX: 4294967295
 SSIZE_MAX: 2147483647
@@ -25,3 +29,11 @@ UINT8_MAX: 255
 UINT16_MAX: 65535
 UINT32_MAX: 4294967295
 UINT64_MAX: 18446744073709551615
+INT8_C: (d) 42
+INT16_C: (d) 42
+INT32_C: (d) 42
+INT64_C: (lld) 42
+INTU8_C: (u) 42
+INTU16_C: (u) 42
+INTU32_C: (u) 42
+INTU64_C: (llu) 42