Transform (sub 0, (zext bool to A)) to (sext bool to A) and
(sub 0, (sext bool to A)) to (zext bool to A).

Patch by Muhammad Ahmad
Reviewed by Duncan Sands


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173093 91177308-0d34-0410-b5e6-96231b3b80d8
Make AttributeSet::getFnAttributes() return an AttributeSet instead of an Attribute.

This is more code to isolate the use of the Attribute class to that of just
holding one attribute instead of a collection of attributes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173094 91177308-0d34-0410-b5e6-96231b3b80d8