Check only if we have this attribute. If it's not an attribute, then it's assumed false.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189063 91177308-0d34-0410-b5e6-96231b3b80d8
Fix some tests. The 'false' version just omits the attribute altogether.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189065 91177308-0d34-0410-b5e6-96231b3b80d8
Update to remove the no-frame-pointer-elim-non-leaf flag if it was set to 'false'.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189068 91177308-0d34-0410-b5e6-96231b3b80d8