Update sema test

Author: hoodmane

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -12998,9 +12998,9 @@ def err_wasm_builtin_arg_must_match_table_element_type : Error <
 def err_wasm_builtin_arg_must_be_integer_type : Error <
   "%ordinal0 argument must be an integer">;
 def err_wasm_builtin_test_fp_sig_cannot_include_reference_type
-    : Error<"__builtin_wasm_test_function_pointer_signature not supported for "
-            "function pointers with reference types in their "
-            "%select{return|parameter}0 type">;
+    : Error<"not supported for "
+            "function pointers with a reference type %select{return "
+            "value|parameter}0">;
 
 // OpenACC diagnostics.
 def warn_acc_routine_unimplemented

clang/test/Sema/builtins-wasm.c

@@ -50,3 +50,27 @@ void test_table_copy(int dst_idx, int src_idx, int nelem) {
   __builtin_wasm_table_copy(table, table, dst_idx, src_idx, table);    // expected-error {{5th argument must be an integer}}
   __builtin_wasm_table_copy(table, table, dst_idx, src_idx, nelem);
 }
+
+typedef void (*F1)(void);
+typedef int (*F2)(int);
+typedef int (*F3)(__externref_t);
+typedef __externref_t (*F4)(int);
+
+void test_function_pointer_signature() {
+  // Test argument count validation
+  (void)__builtin_wasm_test_function_pointer_signature(); // expected-error {{too few arguments to function call, expected 1, have 0}}
+  (void)__builtin_wasm_test_function_pointer_signature((F1)0, (F2)0); // expected-error {{too many arguments to function call, expected 1, have 2}}
+
+  // // Test argument type validation - should require function pointer
+  (void)__builtin_wasm_test_function_pointer_signature((void*)0); // expected-error {{used type 'void *' where function pointer is required}}
+  (void)__builtin_wasm_test_function_pointer_signature((int)0);   // expected-error {{used type 'int' where function pointer is required}}
+  (void)__builtin_wasm_test_function_pointer_signature((F3)0);   // expected-error {{not supported for function pointers with a reference type parameter}}
+  (void)__builtin_wasm_test_function_pointer_signature((F4)0);   // expected-error {{not supported for function pointers with a reference type return value}}
+
+  // // Test valid usage
+  int res = __builtin_wasm_test_function_pointer_signature((F1)0);
+  res = __builtin_wasm_test_function_pointer_signature((F2)0);
+
+  // Test return type
+  _Static_assert(EXPR_HAS_TYPE(__builtin_wasm_test_function_pointer_signature((F1)0), int), "");
+}