[webkit.UncountedLambdaCapturesChecker] Fix debug assertion failure. (#117090)

Only call getThisType() on an instance method.

Author: rniwa

clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp

@@ -51,7 +51,8 @@ class UncountedLambdaCapturesChecker
 
       bool TraverseCXXMethodDecl(CXXMethodDecl *CXXMD) override {
         llvm::SaveAndRestore SavedDecl(ClsType);
-        ClsType = CXXMD->getThisType();
+        if (CXXMD && CXXMD->isInstance())
+          ClsType = CXXMD->getThisType();
         return DynamicRecursiveASTVisitor::TraverseCXXMethodDecl(CXXMD);
       }
 

clang/test/Analysis/Checkers/WebKit/uncounted-lambda-captures.cpp

@@ -1,5 +1,9 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=webkit.UncountedLambdaCapturesChecker -verify %s
 
+struct A {
+  static void b();
+};
+
 struct RefCountable {
   void ref() {}
   void deref() {}