Create android x86_32 and x86_64 target info

On android x86_32 the long double is only 64 bits (compared to 80 bits
on linux x86_32) and on android x86_64 the long double is IEEEquad
(compared to x87DoubleExtended on linux x86_64). This CL creates new
TargetInfo classes for this targets to represent these differences.

Differential revision: http://reviews.llvm.org/D8357

llvm-svn: 233177