[dev.ssa] cmd/compile: provide default types for all extension ops

Change-Id: I655327818297cc6792c81912f2cebdc321381561
Reviewed-on: https://go-review.googlesource.com/24465
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/cmd/compile/internal/ssa/gen/genericOps.go

@@ -327,16 +327,16 @@ var genericOps = []opData{
 	// Conversions: signed extensions, zero (unsigned) extensions, truncations
 	{name: "SignExt8to16", argLength: 1, typ: "Int16"},
 	{name: "SignExt8to32", argLength: 1, typ: "Int32"},
-	{name: "SignExt8to64", argLength: 1},
+	{name: "SignExt8to64", argLength: 1, typ: "Int64"},
 	{name: "SignExt16to32", argLength: 1, typ: "Int32"},
-	{name: "SignExt16to64", argLength: 1},
-	{name: "SignExt32to64", argLength: 1},
+	{name: "SignExt16to64", argLength: 1, typ: "Int64"},
+	{name: "SignExt32to64", argLength: 1, typ: "Int64"},
 	{name: "ZeroExt8to16", argLength: 1, typ: "UInt16"},
 	{name: "ZeroExt8to32", argLength: 1, typ: "UInt32"},
-	{name: "ZeroExt8to64", argLength: 1},
+	{name: "ZeroExt8to64", argLength: 1, typ: "UInt64"},
 	{name: "ZeroExt16to32", argLength: 1, typ: "UInt32"},
-	{name: "ZeroExt16to64", argLength: 1},
-	{name: "ZeroExt32to64", argLength: 1},
+	{name: "ZeroExt16to64", argLength: 1, typ: "UInt64"},
+	{name: "ZeroExt32to64", argLength: 1, typ: "UInt64"},
 	{name: "Trunc16to8", argLength: 1},
 	{name: "Trunc32to8", argLength: 1},
 	{name: "Trunc32to16", argLength: 1},