[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

llvm-svn: 279129
diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index ef45217..55e9b5d 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -1906,7 +1906,7 @@
   }
   // Turn FP truncstore into trunc + store.
   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
-  // Turn FP extload into load/fextend.
+  // Turn FP extload into load/fpextend.
   for (MVT VT : MVT::fp_valuetypes())
     setLoadExtAction(ISD::EXTLOAD, VT, MVT::f32, Expand);