go.tools/pointer: fix build breakage.

(caused by overlapping pending CLs at commit time).

R=crawshaw
TBR=crawshaw
CC=golang-dev
https://golang.org/cl/12820048

pointer/pointer_test.go

@@ -188,7 +188,7 @@ func doOneInput(input, filename string) bool {
 	ptrmain := mainpkg // main package for the pointer analysis
 	if mainpkg.Func("main") == nil {
 		// No main function; assume it's a test.
-		ptrmain = prog.CreateTestMainPackage([]*ssa.Package{mainpkg})
+		mainpkg.CreateTestMainFunction()
 		fmt.Printf("%s: synthesized testmain package for test.\n", imp.Fset.Position(f.Package))
 	}