Fix a bunch of places where operator-> was used directly on the return from dyn_cast.

Inspired by r331508, I did a grep and found these.

Mostly just change from dyn_cast to cast. Some cases also showed a dyn_cast result being converted to bool, so those I changed to isa.

llvm-svn: 331577
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
index d659799..e395533 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -755,7 +755,7 @@
   // Create relocations for unconditional branches to function symbols with
   // different execution mode in ELF binaries.
   if (Sym && Sym->isELF()) {
-    unsigned Type = dyn_cast<MCSymbolELF>(Sym)->getType();
+    unsigned Type = cast<MCSymbolELF>(Sym)->getType();
     if ((Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)) {
       if (Asm.isThumbFunc(Sym) && (FixupKind == ARM::fixup_arm_uncondbranch))
         return true;