Fix PR3274: when promoting the condition of a BRCOND node,

Fix PR3274: when promoting the condition of a BRCOND node,
promote from i1 all the way up to the canonical SetCC type.
In order to discover an appropriate type to use, pass
MVT::Other to getSetCCResultType.  In order to be able to
do this, change getSetCCResultType to take a type as an
argument, not a value (this is also more logical).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61542 91177308-0d34-0410-b5e6-96231b3b80d8