Fix PR18165: LSR must avoid scaling factors that exceed the limit on truncated use.

Patch by Michael Zolotukhin!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202273 91177308-0d34-0410-b5e6-96231b3b80d8
Move these functions out of line. A DenseMap lookup is not a simple operation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202274 91177308-0d34-0410-b5e6-96231b3b80d8