style: modernize to splitseq, cut, min, maps.copy and range-over-int

verify/arm64_groundtruth_test.go

@@ -54,10 +54,7 @@ func TestGroundTruthARM64(t *testing.T) {
 				// The Go toolchain may add zero padding at the end of
 				// functions.  Compare up to the shorter length, then
 				// verify any trailing bytes are zero.
-				cmpLen := len(gasmCode)
-				if len(goCode) < cmpLen {
-					cmpLen = len(goCode)
-				}
+				cmpLen := min(len(goCode), len(gasmCode))
 				if !bytes.Equal(gasmCode[:cmpLen], goCode[:cmpLen]) {
 					t.Errorf("%s: MISMATCH gasm=%d go=%d bytes\n%s", fn.Name, len(gasmCode), len(goCode), diffHex(gasmCode, goCode))
 					continue