cmd/compile: remove Greater* and Geq* generic integer ops

The generic Greater and Geq ops can always be replaced with the Less and
Leq ops. This CL therefore removes them. This simplifies the compiler since
it reduces the number of operations that need handling in both code and in
rewrite rules. This will be especially true when adding control flow
optimizations such as the integer-in-range optimizations in CL 165998.

Change-Id: If0648b2b19998ac1bddccbf251283f3be4ec3040
Reviewed-on: https://go-review.googlesource.com/c/go/+/220417
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

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

@@ -2466,24 +2466,8 @@ const (
 	OpLeq64U
 	OpLeq32F
 	OpLeq64F
-	OpGreater8
-	OpGreater8U
-	OpGreater16
-	OpGreater16U
-	OpGreater32
-	OpGreater32U
-	OpGreater64
-	OpGreater64U
 	OpGreater32F
 	OpGreater64F
-	OpGeq8
-	OpGeq8U
-	OpGeq16
-	OpGeq16U
-	OpGeq32
-	OpGeq32U
-	OpGeq64
-	OpGeq64U
 	OpGeq32F
 	OpGeq64F
 	OpCondSelect
@@ -31925,46 +31909,6 @@ var opcodeTable = [...]opInfo{
 		argLen:  2,
 		generic: true,
 	},
-	{
-		name:    "Greater8",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater8U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater16",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater16U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater32",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater32U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater64",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Greater64U",
-		argLen:  2,
-		generic: true,
-	},
 	{
 		name:    "Greater32F",
 		argLen:  2,
@@ -31975,46 +31919,6 @@ var opcodeTable = [...]opInfo{
 		argLen:  2,
 		generic: true,
 	},
-	{
-		name:    "Geq8",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq8U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq16",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq16U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq32",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq32U",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq64",
-		argLen:  2,
-		generic: true,
-	},
-	{
-		name:    "Geq64U",
-		argLen:  2,
-		generic: true,
-	},
 	{
 		name:    "Geq32F",
 		argLen:  2,