Match gccgo error messages.

I have to admit that "cannot use type p.T as type p.T" is a
bit weak.  8g gives a similar error ("cannot use v1 (type p.T)
as type p.T in assignment").

bug3.go:37:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different parameter types))
bug3.go:38:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different parameter types))
bug3.go:43:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different parameter types))
bug3.go:44:5: error: incompatible type in initialization (incompatible type for method ‘M’ (different parameter types))
bug3.go:49:5: error: incompatible types in assignment (cannot use type p.T as type p.T)
bug3.go:50:5: error: incompatible types in assignment (cannot use type p.T as type p.T)
bug3.go:55:5: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:56:5: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:57:6: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:58:6: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:59:5: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:60:5: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:61:6: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))
bug3.go:62:6: error: incompatible types in assignment (incompatible type for method ‘M’ (different parameter types))

R=rsc
CC=golang-dev
https://golang.org/cl/199044

test/fixedbugs/bug248.dir/bug3.go

@@ -34,14 +34,14 @@ func (t1) M(p1.T) {}
 var i0 I0 = t0(0) // ok
 var i1 I1 = t1(0) // ok
 
-var i2 I0 = t1(0) // ERROR "is not"
-var i3 I1 = t0(0) // ERROR "is not"
+var i2 I0 = t1(0) // ERROR "is not|incompatible"
+var i3 I1 = t0(0) // ERROR "is not|incompatible"
 
 var p0i p0.I = t0(0) // ok
 var p1i p1.I = t1(0) // ok
 
-var p0i1 p0.I = t1(0) // ERROR "is not"
-var p0i2 p1.I = t0(0) // ERROR "is not"
+var p0i1 p0.I = t1(0) // ERROR "is not|incompatible"
+var p0i2 p1.I = t0(0) // ERROR "is not|incompatible"
 
 func main() {
 	// check that cannot assign one to the other,
@@ -52,14 +52,14 @@ func main() {
 	v0 = p0.T(v1)
 	v1 = p1.T(v0)
 
-	i0 = i1   // ERROR "need type assertion"
-	i1 = i0   // ERROR "need type assertion"
-	p0i = i1  // ERROR "need type assertion"
-	p1i = i0  // ERROR "need type assertion"
-	i0 = p1i  // ERROR "need type assertion"
-	i1 = p0i  // ERROR "need type assertion"
-	p0i = p1i // ERROR "need type assertion"
-	p1i = p0i // ERROR "need type assertion"
+	i0 = i1   // ERROR "need type assertion|incompatible"
+	i1 = i0   // ERROR "need type assertion|incompatible"
+	p0i = i1  // ERROR "need type assertion|incompatible"
+	p1i = i0  // ERROR "need type assertion|incompatible"
+	i0 = p1i  // ERROR "need type assertion|incompatible"
+	i1 = p0i  // ERROR "need type assertion|incompatible"
+	p0i = p1i // ERROR "need type assertion|incompatible"
+	p1i = p0i // ERROR "need type assertion|incompatible"
 
 	i0 = p0i
 	p0i = i0