[clang-tidy] fix cppcoreguidelines-init-variables with catch variables

[njames93]

Summary

Ignore catch statement var decls.

[njames93]

Remove unneeded include

[njames93]

New line at end of file

[aaron.ballman]

LGTM!

clang-tools-extra/clang-tidy/cppcoreguidelines/InitVariablesCheck.cpp

void InitVariablesCheck::storeOptions(ClangTidyOptions::OptionMap &Opts) {
   Options.store(Opts, "MathHeader", MathHeader);
 }
 
 void InitVariablesCheck::registerMatchers(MatchFinder *Finder) {
   std::string BadDecl = "badDecl";
   Finder->addMatcher(
       varDecl(unless(hasInitializer(anything())), unless(isInstantiated()),
               isLocalVarDecl(), unless(isStaticLocal()), isDefinition(),
+              unless(hasParent(cxxCatchStmt())),
               optionally(hasParent(declStmt(hasParent(
                   cxxForRangeStmt(hasLoopVariable(varDecl().bind(BadDecl))))))),
               unless(equalsBoundNode(BadDecl)))
           .bind("vardecl"),
       this);
 }
 
 void InitVariablesCheck::registerPPCallbacks(const SourceManager &SM,

clang-tools-extra/test/clang-tidy/checkers/cppcoreguidelines-init-variables.cpp

-// RUN: %check_clang_tidy %s cppcoreguidelines-init-variables %t -- -- -fno-delayed-template-parsing
+// RUN: %check_clang_tidy %s cppcoreguidelines-init-variables %t -- -- -fno-delayed-template-parsing -fexceptions
 
 // Ensure that function declarations are not changed.
 void some_func(int x, double d, bool b, const char *p);
 
 // Ensure that function arguments are not changed
 int identity_function(int x) {
   return x;
 }
void init_unit_tests() {
   int braces{42};
 }
 
 template <typename RANGE>
 void f(RANGE r) {
   for (char c : r) {
   }
 }
+
+void catch_variable_decl() {
+  // Expect no warning given here.
+  try {
+  } catch (int X) {
+  }
+}