go/types, types2: fix failing error message test for s390x

Fixes #73206.

Change-Id: If27ce5fe7aa71415b6e2d525c78b1f04b88a308b
Reviewed-on: https://go-review.googlesource.com/c/go/+/663635
TryBot-Result: Gopher Robot <[email protected]>
TryBot-Bypass: Dmitri Shuralyov <[email protected]>
Reviewed-by: Robert Griesemer <[email protected]>
Reviewed-by: Mark Freeman <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

Author: Mark Freeman

src/internal/types/testdata/fixedbugs/issue70549.go

@@ -7,9 +7,9 @@ package p
 import "math"
 
 var (
-	_ = math.Sin
-	_ = math.SIn /* ERROR "undefined: math.SIn (but have Sin)" */
-	_ = math.sin /* ERROR "name sin not exported by package math" */
-	_ = math.Foo /* ERROR "undefined: math.Foo" */
-	_ = math.foo /* ERROR "undefined: math.foo" */
+	_ = math.Sqrt
+	_ = math.SQrt /* ERROR "undefined: math.SQrt (but have Sqrt)" */
+	_ = math.sqrt /* ERROR "name sqrt not exported by package math" */
+	_ = math.Foo  /* ERROR "undefined: math.Foo" */
+	_ = math.foo  /* ERROR "undefined: math.foo" */
 )