[ConstantRange] Add getFull() + getEmpty() named constructors; NFC
This adds ConstantRange::getFull(BitWidth) and
ConstantRange::getEmpty(BitWidth) named constructors as more readable
alternatives to the current ConstantRange(BitWidth, /* full */ false)
and similar. Additionally private getFull() and getEmpty() member
functions are added which return a full/empty range with the same bit
width -- these are commonly needed inside ConstantRange.cpp.
The IsFullSet argument in the ConstantRange(BitWidth, IsFullSet)
constructor is now mandatory for the few usages that still make use of it.
Differential Revision: https://reviews.llvm.org/D59716
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356852 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed