when no virtual registers have been allocated.
It was only used to resize IndexedMaps, so provide an IndexedMap::resize()
method such that
Map.grow(MRI.getLastVirtReg());
can be replaced with the simpler
Map.resize(MRI.getNumVirtRegs());
This works correctly when no virtuals are allocated, and it bypasses the to/from
index conversions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123130 91177308-0d34-0410-b5e6-96231b3b80d8