[NFC][clangd] fix clang-tidy finding on isa_and_nonnull

[kuhnel]

Summary

This is a cleanup of the only llvm-prefer-isa-or-dyn-cast-in-conditionals finding in the clangd code base. This patch was created by automatically applying the fixes from clang-tidy.

[kadircet]

clang-tools-extra/clangd/Selection.cpp

503

while here llvm::isa_and_nonnull we try to qualify symbols from llvm namespace.

[kuhnel]

clang-tools-extra/clangd/Selection.cpp

503

Sorry, I'm not getting what you wanted to say.

You want me to add a llvm::?
Or is it about a operator bool()(however I didn't find one for Decl )?

[kadircet]

thanks!

clang-tools-extra/clangd/Selection.cpp

503

You want me to add a llvm::?

right, I was asking for qualifying the symbol with llvm:: namespace specifier.

clang-tools-extra/clangd/Selection.cpp

public:
   //  - pop it from the stack
   //  - hit testing: is intersection(node, selection) - union(children) empty?
   //  - attach it to the tree if it or any children hit the selection
   //
   // Two categories of nodes are not "well-behaved":
   //  - those without source range information, we don't record those
   //  - those that can't be stored in DynTypedNode.
   bool TraverseDecl(Decl *X) {
-    if (X && isa<TranslationUnitDecl>(X))
+    if (llvm::isa_and_nonnull<TranslationUnitDecl>(X))
       return Base::TraverseDecl(X); // Already pushed by constructor.
     // Base::TraverseDecl will suppress children, but not this node itself.
     if (X && X->isImplicit())
       return true;
     return traverseNode(X, [&] { return Base::TraverseDecl(X); });
   }
   bool TraverseTypeLoc(TypeLoc X) {
     return traverseNode(&X, [&] { return Base::TraverseTypeLoc(X); });