[analyzer] Rename assumeWithinInclusiveRange*()

Summary: The name is slightly confusing, since the constraint is not necessarily within the range unless `Assumption` is true. Split out renaming for ConstraintManager.h from D26061

Reviewers: zaks.anna, dcoughlin

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D26644

llvm-svn: 286927