[NFC][Clang] Use isa_and_nonnull instead of VD && isa<VarDecl>(VD) (#93207)

This issue was found in #86960.
But I'd like to avoid mixing together a bunch of cleanups with actual
changes.

Signed-off-by: yronglin <[email protected]>

Author: yronglin

clang/lib/CodeGen/CGExpr.cpp

@@ -317,8 +317,8 @@ pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
         CleanupKind CleanupKind;
         if (Lifetime == Qualifiers::OCL_Strong) {
           const ValueDecl *VD = M->getExtendingDecl();
-          bool Precise =
-              VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
+          bool Precise = isa_and_nonnull<VarDecl>(VD) &&
+                         VD->hasAttr<ObjCPreciseLifetimeAttr>();
           CleanupKind = CGF.getARCCleanupKind();
           Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
                             : &CodeGenFunction::destroyARCStrongImprecise;