cmd/gc: don't dereference a nil Type pointer in widstruct
The nil dereference in the next few lines doesn't seem
to cause a segmentation fault on Unix, but does seem
to halt the Go compiler.
The following is a test case:
>>>
package main
func mine(int b) int {
return b + 2
}
func main() {
mine()
c = mine()
}
<<<
Without this change only the following is caught:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
with it, we catch all the errors:
typecheck.go:3: undefined: b
typecheck.go:4: undefined: b
typecheck.go:10: undefined: c
typecheck.go:10: cannot assign to c .
R=rsc, minux.ma
CC=golang-dev
https://golang.org/cl/
6542060