cmd/compile/internal/gc: remove oconv(op, 0) calls

Updates #15462

Automatic refactor with sed -e.

Replace all oconv(op, 0) to string conversion with the raw op value
which fmt's %v verb can print directly.

The remaining oconv(op, FmtSharp) will be replaced with op.GoString and
%#v in the next CL.

Change-Id: I5e2f7ee0bd35caa65c6dd6cb1a866b5e4519e641
Reviewed-on: https://go-review.googlesource.com/22499
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/gc/ssa.go b/src/cmd/compile/internal/gc/ssa.go
index 1006fcd..b31cd87 100644
--- a/src/cmd/compile/internal/gc/ssa.go
+++ b/src/cmd/compile/internal/gc/ssa.go
@@ -2560,7 +2560,7 @@
 		// want to set it here.
 	case OCALLINTER:
 		if fn.Op != ODOTINTER {
-			Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", oconv(fn.Op, 0))
+			Fatalf("OCALLINTER: n.Left not an ODOTINTER: %v", fn.Op)
 		}
 		i := s.expr(fn.Left)
 		itab := s.newValue1(ssa.OpITab, Types[TUINTPTR], i)
@@ -2784,7 +2784,7 @@
 		return s.call(n, callNormal)
 
 	default:
-		s.Unimplementedf("unhandled addr %v", oconv(n.Op, 0))
+		s.Unimplementedf("unhandled addr %v", n.Op)
 		return nil
 	}
 }