[FMV] -Wunused-function incorrectly complains about versioned static functions

[jroelofs]

https://clang.godbolt.org/z/7zdKf8M9r

__attribute__((target_version("fp16")))
static int foo(void) { return 1; }

__attribute__((target_version("fp16fml")))
static int foo(void) { return 2; }

__attribute__((target_version("default")))
static int foo(void) { return 0; }

int caller() {
    return foo();
}

-Wunused-function -Werror

<source>:2:12: error: unused function 'foo' [-Werror,-Wunused-function]
    2 | static int foo(void) { return 1; }
      |            ^~~
<source>:5:12: error: unused function 'foo' [-Werror,-Wunused-function]
    5 | static int foo(void) { return 2; }

[jroelofs]

cc @ilinpv @labrinea

[llvmbot]

@llvm/issue-subscribers-bug

Author: Jon Roelofs (jroelofs)

https://clang.godbolt.org/z/7zdKf8M9r

__attribute__((target_version("fp16")))
static int foo(void) { return 1; }

__attribute__((target_version("fp16fml")))
static int foo(void) { return 2; }

__attribute__((target_version("default")))
static int foo(void) { return 0; }

int caller() {
    return foo();
}

-Wunused-function -Werror

<source>:2:12: error: unused function 'foo' [-Werror,-Wunused-function]
    2 | static int foo(void) { return 1; }
      |            ^~~
<source>:5:12: error: unused function 'foo' [-Werror,-Wunused-function]
    5 | static int foo(void) { return 2; }

[jroelofs]

dupe of #80227