test new slices

R=r
CC=golang-dev
https://golang.org/cl/2128047

test/ken/slicearray.go

@@ -33,12 +33,18 @@ func main() {
 	tstb()
 	by = bx[lb:]
 	tstb()
+	by = bx[:hb]
+	tstb()
 	by = bx[0:hb]
 	tstb()
 	by = bx[0:10]
 	tstb()
 	by = bx[0:]
 	tstb()
+	by = bx[:10]
+	tstb()
+	by = bx[:]
+	tstb()
 
 	lb = 2
 	hb = 10
@@ -65,6 +71,10 @@ func main() {
 	tstb()
 	by = bx[0:8]
 	tstb()
+	by = bx[:8]
+	tstb()
+	by = bx[:hb]
+	tstb()
 
 	lb = 2
 	hb = 8
@@ -86,12 +96,18 @@ func main() {
 	tstf()
 	fy = fx[lb:]
 	tstf()
+	fy = fx[:hb]
+	tstf()
 	fy = fx[0:hb]
 	tstf()
 	fy = fx[0:10]
 	tstf()
 	fy = fx[0:]
 	tstf()
+	fy = fx[:10]
+	tstf()
+	fy = fx[:]
+	tstf()
 
 	lb = 2
 	hb = 10
@@ -114,10 +130,14 @@ func main() {
 	tstf()
 	fy = fx[lb:8]
 	tstf()
+	fy = fx[:hb]
+	tstf()
 	fy = fx[0:hb]
 	tstf()
 	fy = fx[0:8]
 	tstf()
+	fy = fx[:8]
+	tstf()
 
 	lb = 2
 	hb = 8

test/ken/sliceslice.go

@@ -24,12 +24,18 @@ func main() {
 	tstb()
 	by = bx[lb:]
 	tstb()
+	by = bx[:hb]
+	tstb()
 	by = bx[0:hb]
 	tstb()
 	by = bx[0:10]
 	tstb()
 	by = bx[0:]
 	tstb()
+	by = bx[:10]
+	tstb()
+	by = bx[:]
+	tstb()
 
 	lb = 2
 	hb = 10
@@ -56,6 +62,10 @@ func main() {
 	tstb()
 	by = bx[0:8]
 	tstb()
+	by = bx[:8]
+	tstb()
+	by = bx[:hb]
+	tstb()
 
 	lb = 2
 	hb = 8
@@ -77,12 +87,18 @@ func main() {
 	tstf()
 	fy = fx[lb:]
 	tstf()
+	fy = fx[:hb]
+	tstf()
 	fy = fx[0:hb]
 	tstf()
 	fy = fx[0:10]
 	tstf()
 	fy = fx[0:]
 	tstf()
+	fy = fx[:10]
+	tstf()
+	fy = fx[:]
+	tstf()
 
 	lb = 2
 	hb = 10
@@ -105,10 +121,14 @@ func main() {
 	tstf()
 	fy = fx[lb:8]
 	tstf()
+	fy = fx[:hb]
+	tstf()
 	fy = fx[0:hb]
 	tstf()
 	fy = fx[0:8]
 	tstf()
+	fy = fx[:8]
+	tstf()
 
 	lb = 2
 	hb = 8