Revert "Don't invoke getName() from Function::isIntrinsic().", rL276942.

This broke some out-of-tree AMDGPU tests that relied on the old behavior
wherein isIntrinsic() would return true for any function that starts
with "llvm.".  And in general that change will not play nicely with
out-of-tree backends.

llvm-svn: 277087
diff --git a/llvm/lib/CodeGen/WinEHPrepare.cpp b/llvm/lib/CodeGen/WinEHPrepare.cpp
index 28efee0..041fb7b 100644
--- a/llvm/lib/CodeGen/WinEHPrepare.cpp
+++ b/llvm/lib/CodeGen/WinEHPrepare.cpp
@@ -949,14 +949,10 @@
           continue;
 
         // Skip call sites which are nounwind intrinsics or inline asm.
-        //
-        // FIXME: Should this check isIntrinsic() instead of
-        // hasLLVMReservedName?  The latter is conservative.
         auto *CalledFn =
             dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts());
-        if (CalledFn &&
-            ((CalledFn->hasLLVMReservedName() && CS.doesNotThrow()) ||
-             CS.isInlineAsm()))
+        if (CalledFn && ((CalledFn->isIntrinsic() && CS.doesNotThrow()) ||
+                         CS.isInlineAsm()))
           continue;
 
         // This call site was not part of this funclet, remove it.