[clang-tidy][NFC] Enable misc-const-correctness rule in clang-tidy codebase (#167172)

After successful `misc-const-correctness` cleanup (last patch
#167131), we can enable
`misc-const-correctness` rule for the whole project.

During cleanup, I didn't encounter any false positives so it's safe to
assume that we will have minimal FP in the future.

Author: vbvictor

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

@@ -9,6 +9,7 @@ Checks: >
   -bugprone-narrowing-conversions,
   -bugprone-unchecked-optional-access,
   -bugprone-unused-return-value,
+  misc-const-correctness,
   modernize-*,
   -modernize-avoid-c-arrays,
   -modernize-pass-by-value,

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

@@ -600,13 +600,14 @@ ExceptionAnalyzer::throwsException(const Stmt *St,
     // whether the call itself throws.
     if (const auto *Call = dyn_cast<CallExpr>(St)) {
       if (const FunctionDecl *Func = Call->getDirectCallee()) {
-        ExceptionInfo Excs =
+        const ExceptionInfo Excs =
             throwsException(Func, Caught, CallStack, Call->getBeginLoc());
         Results.merge(Excs);
       }
     } else if (const auto *Construct = dyn_cast<CXXConstructExpr>(St)) {
-      ExceptionInfo Excs = throwsException(Construct->getConstructor(), Caught,
-                                           CallStack, Construct->getBeginLoc());
+      const ExceptionInfo Excs =
+          throwsException(Construct->getConstructor(), Caught, CallStack,
+                          Construct->getBeginLoc());
       Results.merge(Excs);
     }
   }