[dev.ssa] cmd/compile/internal/ssa: implement OSQRT

Change-Id: Iec61ca1bdc064c29ceca6d47f600d5643d0a64dd
Reviewed-on: https://go-review.googlesource.com/14533
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/src/cmd/compile/internal/ssa/gen/genericOps.go b/src/cmd/compile/internal/ssa/gen/genericOps.go
index a949764..dcaff95 100644
--- a/src/cmd/compile/internal/ssa/gen/genericOps.go
+++ b/src/cmd/compile/internal/ssa/gen/genericOps.go
@@ -232,6 +232,8 @@
 	{name: "Com32"},
 	{name: "Com64"},
 
+	{name: "Sqrt"}, // sqrt(arg0), float64 only
+
 	// Data movement
 	{name: "Phi"},  // select an argument based on which predecessor block we came from
 	{name: "Copy"}, // output = arg0