Fix selection of std lib result by excluding unwrapped elements

Author: MichaelRFairhurst

cpp/misra/src/rules/RULE-4-1-1/CompilerLanguageExtensionsUsed.ql

@@ -20,6 +20,8 @@ import codingstandards.cpp.misra
 import codingstandards.cpp.Extensions
 import codingstandards.cpp.AlertReporting
 
-from CPPCompilerExtension e
-where not isExcluded(e, Toolchain2Package::compilerLanguageExtensionsUsedQuery())
-select MacroUnwrapper<CPPCompilerExtension>::unwrapElement(e), e.getMessage()
+from Element unwrapped, CPPCompilerExtension e
+where
+  not isExcluded([e, unwrapped], Toolchain2Package::compilerLanguageExtensionsUsedQuery()) and
+  unwrapped = MacroUnwrapper<CPPCompilerExtension>::unwrapElement(e)
+select unwrapped, e.getMessage()

cpp/misra/test/rules/RULE-4-1-1/CompilerLanguageExtensionsUsed.expected

@@ -1,4 +1,3 @@
-| file:///Users/michaelrfairhurst/projects/codeql-coding-standards/cpp/common/test/includes/standard-library/stdarg.h:5:1:5:47 | #define va_start(v,l) __builtin_va_start(v, l) | Use of built-in operation '__builtin_va_start' is a compiler extension. |
 | test.cpp:11:3:11:19 | maybe_unused | Use of attribute 'maybe_unused' in namespace 'gnu' is a compiler extension and is not portable to other compilers. |
 | test.cpp:12:16:12:22 | aligned | Use of attribute 'aligned' is a compiler extension and is not portable to other compilers. |
 | test.cpp:13:16:13:21 | unused | Use of attribute 'unused' is a compiler extension and is not portable to other compilers. |