[IPSCCP] Move common functions to ValueLatticeUtils (NFC)

This patch moves some common utility functions out of IPSCCP and makes them
available globally. The functions determine if interprocedural data-flow
analyses can propagate information through function returns, arguments, and
global variables.

Differential Revision: https://reviews.llvm.org/D37638

llvm-svn: 315719
diff --git a/llvm/lib/Analysis/CMakeLists.txt b/llvm/lib/Analysis/CMakeLists.txt
index f98cb52..af2e30d 100644
--- a/llvm/lib/Analysis/CMakeLists.txt
+++ b/llvm/lib/Analysis/CMakeLists.txt
@@ -81,6 +81,7 @@
   TypeMetadataUtils.cpp
   ScopedNoAliasAA.cpp
   ValueLattice.cpp
+  ValueLatticeUtils.cpp
   ValueTracking.cpp
   VectorUtils.cpp