[BPI] Replace weights by probabilities in BPI.

This patch removes all weight-related interfaces from BPI and replace
them by probability versions. With this patch, we won't use edge weight
anymore in either IR or MC passes. Edge probabilitiy is a better
representation in terms of CFG update and validation.


Differential revision: http://reviews.llvm.org/D15519 

llvm-svn: 256263
diff --git a/llvm/test/Transforms/JumpThreading/update-edge-weight.ll b/llvm/test/Transforms/JumpThreading/update-edge-weight.ll
index b5c5d01..58cd718 100644
--- a/llvm/test/Transforms/JumpThreading/update-edge-weight.ll
+++ b/llvm/test/Transforms/JumpThreading/update-edge-weight.ll
@@ -2,7 +2,7 @@
 
 ; Test if edge weights are properly updated after jump threading.
 
-; CHECK: !2 = !{!"branch_weights", i32 22, i32 7}
+; CHECK: !2 = !{!"branch_weights", i32 1629125526, i32 518358122}
 
 define void @foo(i32 %n) !prof !0 {
 entry: