[clang-tidy] add misc-constexpr check

This check finds all functions and variables that can be declared as
`constexpr`, using the specified standard version to check if the
requirements are met.

Fixes #115622

Author: 5chmidti

clang-tools-extra/clang-tidy/misc/CMakeLists.txt

@@ -19,6 +19,7 @@ set_target_properties(genconfusable PROPERTIES FOLDER "Clang Tools Extra/Sourceg
 
 add_clang_library(clangTidyMiscModule STATIC
   ConstCorrectnessCheck.cpp
+  UseConstexprCheck.cpp
   CoroutineHostileRAIICheck.cpp
   DefinitionsInHeadersCheck.cpp
   ConfusableIdentifierCheck.cpp

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

@@ -31,6 +31,7 @@
 #include "UnusedParametersCheck.h"
 #include "UnusedUsingDeclsCheck.h"
 #include "UseAnonymousNamespaceCheck.h"
+#include "UseConstexprCheck.h"
 #include "UseInternalLinkageCheck.h"
 
 namespace clang::tidy {
@@ -43,6 +44,7 @@ class MiscModule : public ClangTidyModule {
         "misc-confusable-identifiers");
     CheckFactories.registerCheck<ConstCorrectnessCheck>(
         "misc-const-correctness");
+    CheckFactories.registerCheck<UseConstexprCheck>("misc-use-constexpr");
     CheckFactories.registerCheck<CoroutineHostileRAIICheck>(
         "misc-coroutine-hostile-raii");
     CheckFactories.registerCheck<DefinitionsInHeadersCheck>(