[clang-tidy][use-internal-linkage] fix false positive for consteval function (#122141)

Fixes #122096

---------

Co-authored-by: MarcoFalke <*~=`'#}+{/-|&$^[email protected]>

Author: maflcko

clang-tools-extra/clang-tidy/misc/UseInternalLinkageCheck.cpp

@@ -125,7 +125,7 @@ void UseInternalLinkageCheck::registerMatchers(MatchFinder *Finder) {
                     exportDecl()))))));
   Finder->addMatcher(
       functionDecl(Common, hasBody(),
-                   unless(anyOf(cxxMethodDecl(),
+                   unless(anyOf(cxxMethodDecl(), isConsteval(),
                                 isAllocationOrDeallocationOverloadedFunction(),
                                 isMain())))
           .bind("fn"),

clang-tools-extra/docs/ReleaseNotes.rst

@@ -286,9 +286,9 @@ Changes in existing checks
 
 - Improved :doc:`misc-use-internal-linkage
   <clang-tidy/checks/misc/use-internal-linkage>` check to insert ``static``
-  keyword before type qualifiers such as ``const`` and ``volatile`` and fix
-  false positives for function declaration without body and fix false positives
-  for C++20 export declarations and fix false positives for global scoped
+  keyword before type qualifiers such as ``const`` and ``volatile``. Also, fix
+  false positives for function declaration without body, C++20 consteval
+  functions, C++20 export declarations, and global scoped
   overloaded ``operator new`` and ``operator delete``.
 
 - Improved :doc:`modernize-avoid-c-arrays

clang-tools-extra/test/clang-tidy/checkers/misc/use-internal-linkage-consteval.cpp

@@ -0,0 +1,7 @@
+// RUN: %check_clang_tidy -std=c++20 %s misc-use-internal-linkage %t -- -- -I%S/Inputs/use-internal-linkage
+
+consteval void gh122096() {}
+
+constexpr void cxf() {}
+// CHECK-MESSAGES: :[[@LINE-1]]:16: warning: function 'cxf'
+// CHECK-FIXES: static constexpr void cxf() {}