Add TargetInfo for 32-bit and 64-bit RenderScript

Summary:
The TargetInfo for 'renderscript32' and 'renderscript64' ArchTypes are
subclasses of ARMleTargetInfo and AArch64leTargetInfo respectively.

RenderScript32TargetInfo modifies the ARM ABI to set LongWidth and
LongAlign to be 64-bits.  Other than this modification, the underlying
TargetInfo base classes is initialized as if they have "armv7" and
"aarch64" architecture type respectively.

Reviewers: rsmith, echristo

Subscribers: aemerson, tberghammer, cfe-commits, danalbert, mehdi_amini, srhines

Differential Revision: http://reviews.llvm.org/D21334

llvm-svn: 274409