[CodeGenPrepare] Move Extension Instructions Through Logical And Shift Instructions

CodeGenPrepare pass move extension instructions close to load instructions in different BB, so they can be combined later. But the extension instructions can't move through logical and shift instructions in current implementation. This patch enables this enhancement, so we can eliminate more extension instructions.

Differential Revision: https://reviews.llvm.org/D45537

llvm-svn: 331783