[clang] [llvm] [Clang][LoongArch] Support target attribute for function (PR #140700)

[Lu Weining via cfe-commits]

================
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -triple loongarch64-linux-gnu  -fsyntax-only -verify %s
+
+// expected-error at +1 {{function multiversioning is not supported on the current target}}
+void __attribute__((target("default"))) bar(void){}
----------------
SixWeining wrote:

```suggestion
void __attribute__((target("default"))) bar(void) {}
```

https://github.com/llvm/llvm-project/pull/140700