Reapply the new LoopStrengthReduction code, with compile time and

bug fixes, and with improved heuristics for analyzing foreign-loop
addrecs.

This change also flattens IVUsers, eliminating the stride-oriented
groupings, which makes it easier to work with.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95975 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/LoopStrengthReduce/invariant_value_first_arg.ll

@@ -1,5 +1,5 @@
 ; Check that the index of 'P[outer]' is pulled out of the loop.
-; RUN: opt < %s -loop-reduce -S | \
+; RUN: opt < %s -loop-reduce -S -default-data-layout="e-p:32:32:32" | \
 ; RUN:   not grep {getelementptr.*%outer.*%INDVAR}
 
 declare i1 @pred()