cmd/compile/internal/ssa: remove unused OpFunc

Change-Id: I0f7eec2e0c15a355422d5ae7289508a5bd33b971
Reviewed-on: https://go-review.googlesource.com/38171
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

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

@@ -281,10 +281,9 @@ var genericOps = []opData{
 	// or *AutoSymbol (arg0=SP).
 	{name: "Addr", argLength: 1, aux: "Sym", symEffect: "Addr"}, // Address of a variable.  Arg0=SP or SB.  Aux identifies the variable.
 
-	{name: "SP"},                                  // stack pointer
-	{name: "SB", typ: "Uintptr"},                  // static base pointer (a.k.a. globals pointer)
-	{name: "Func", aux: "Sym", symEffect: "None"}, // entry address of a function
-	{name: "Invalid"},                             // unused value
+	{name: "SP"},                 // stack pointer
+	{name: "SB", typ: "Uintptr"}, // static base pointer (a.k.a. globals pointer)
+	{name: "Invalid"},            // unused value
 
 	// Memory operations
 	{name: "Load", argLength: 2},                                  // Load from arg0.  arg1=memory

src/cmd/compile/internal/ssa/opGen.go

@@ -1783,7 +1783,6 @@ const (
 	OpAddr
 	OpSP
 	OpSB
-	OpFunc
 	OpLoad
 	OpStore
 	OpMove
@@ -21552,13 +21551,6 @@ var opcodeTable = [...]opInfo{
 		argLen:  0,
 		generic: true,
 	},
-	{
-		name:      "Func",
-		auxType:   auxSym,
-		argLen:    0,
-		symEffect: SymNone,
-		generic:   true,
-	},
 	{
 		name:    "Load",
 		argLen:  2,