[clang] [clang] Ignore GCC 11 `[[malloc(x)]]` attribute (PR #68059)

[Aaron Ballman via cfe-commits]

================
@@ -1,12 +1,14 @@
-// RUN: %clang_cc1 -verify -Wunused -Wused-but-marked-unused -Wunused-parameter -fsyntax-only %s
+// RUN: %clang_cc1 -verify -Wunused -Wused-but-marked-unused -Wunused-parameter -fsyntax-only -fdeclspec %s
 int a;
 
 inline __attribute__((noreturn(a))) void *f1(void);  // expected-error {{'noreturn' attribute takes no arguments}}
 inline __attribute__((always_inline(a))) void *f2(void);  // expected-error {{'always_inline' attribute takes no arguments}}
 inline __attribute__((cdecl(a))) void *f3(void);  // expected-error {{'cdecl' attribute takes no arguments}}
 inline __attribute__((const(a))) void *f4(void);  // expected-error {{'const' attribute takes no arguments}}
 inline __attribute__((fastcall(a))) void *f5(void);  // expected-error {{'fastcall' attribute takes no arguments}}
-inline __attribute__((malloc(a))) void *f5(void);  // expected-error {{'malloc' attribute takes no arguments}}
+inline __declspec(restrict(a)) void *f6_a(void);  // expected-error {{'restrict' attribute takes no arguments}}
+inline __attribute__((malloc(a, 1, a))) void *f6_b(void);  // expected-error {{'malloc' attribute takes no more than 2 arguments}}
+inline __attribute__((malloc(a, 1))) void *f6_c(void);  // expected-warning {{'malloc' attribute ignored because Clang does not support the one/two argument form}}
----------------
AaronBallman wrote:

One more test I'd like to see is:
```
inline __attribute__((malloc(1))) void *func(void) // error: '1' does not name a function
```


https://github.com/llvm/llvm-project/pull/68059