[SelectionDAG] Rename fextend -> fpextend, fround -> fpround, frnd -> fround

The names of the tablegen defs now match the names of the ISD nodes.
This makes the world a slightly saner place, as previously "fround" matched
ISD::FP_ROUND and not ISD::FROUND.

Differential Revision: https://reviews.llvm.org/D23597


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@279129 91177308-0d34-0410-b5e6-96231b3b80d8
22 files changed