[clang-tidy][NFC] Add a few cppcoreguidelines checks to codebase

clang-tools-extra/clang-tidy/.clang-tidy

@@ -9,6 +9,10 @@ Checks: >
   -bugprone-narrowing-conversions,
   -bugprone-unchecked-optional-access,
   -bugprone-unused-return-value,
+  cppcoreguidelines-init-variables,
+  cppcoreguidelines-missing-std-forward,
+  cppcoreguidelines-rvalue-reference-param-not-moved,
+  cppcoreguidelines-virtual-class-destructor,
   misc-const-correctness,
   modernize-*,
   -modernize-avoid-c-arrays,

clang-tools-extra/clang-tidy/bugprone/UnsafeFunctionsCheck.cpp

@@ -266,8 +266,8 @@ void UnsafeFunctionsCheck::registerMatchers(MatchFinder *Finder) {
 }
 
 void UnsafeFunctionsCheck::check(const MatchFinder::MatchResult &Result) {
-  const Expr *SourceExpr;
-  const FunctionDecl *FuncDecl;
+  const Expr *SourceExpr = nullptr;
+  const FunctionDecl *FuncDecl = nullptr;
 
   if (const auto *DeclRef = Result.Nodes.getNodeAs<DeclRefExpr>(DeclRefId)) {
     SourceExpr = DeclRef;

clang-tools-extra/clang-tidy/utils/UseRangesCheck.cpp

@@ -199,7 +199,7 @@ void UseRangesCheck::check(const MatchFinder::MatchResult &Result) {
     if (!NodeStr.consume_front(FuncDecl))
       continue;
     Function = Value.get<FunctionDecl>();
-    size_t Index;
+    size_t Index = 0;
     if (NodeStr.getAsInteger(10, Index)) {
       llvm_unreachable("Unable to extract replacer index");
     }