[clang-tools-extra] [clang-tidy][NFC] Fix llvm-prefer-static-over-anonymous-namespace warnings N/N (PR #165172)

[Baranov Victor via cfe-commits]

================
@@ -20,6 +20,7 @@ namespace clang::tidy::bugprone {
 
 namespace {
 
+// NOLINTNEXTLINE(llvm-prefer-static-over-anonymous-namespace)
----------------
vbvictor wrote:

The function `isCompleteAndHasNoZeroValue` is used inside `AST_MATCHER(EnumDecl, isCompleteAndHasNoZeroValue)` and as a freestanding function.

If I convert it to static, then there are build errors like:
```
clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp:37:10: error: no matching function for call to 'isCompleteAndHasNoZeroValue'
   37 |   return isCompleteAndHasNoZeroValue(&Node);
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
llvm2/llvm-project/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp:36:23: note: candidate function not viable: requires 0 arguments, but 1 was provided
   36 | AST_MATCHER(EnumDecl, isCompleteAndHasNoZeroValue) {
      |                       ^
llvm2/llvm-project/clang/include/clang/ASTMatchers/ASTMatchersMacros.h:108:57: note: expanded from macro 'AST_MATCHER'
  108 |   inline ::clang::ast_matchers::internal::Matcher<Type> DefineMatcher() {      \
      |                                                         ^
llvm2/llvm-project/clang-tools-extra/clang-tidy/bugprone/InvalidEnumDefaultInitializationCheck.cpp:37:10: error: no viable conversion from returned value of type '::clang::ast_matchers::internal::Matcher<EnumDecl>' to function return type 'bool'
   37 |   return isCompleteAndHasNoZeroValue(&Node);
```

In the past I dodge it by renaming ether matcher of function, but here I think the name is so self-contained that we should leave it as-is..

https://github.com/llvm/llvm-project/pull/165172