compiler: Don't declare blank labels. Fixes issue 7539.
Changes to is_defined are redundant.
Removed other redundant change.
https://codereview.appspot.com/76960044/#msg4
https://codereview.appspot.com/76960044/#msg7
compiler: Don't declare blank labels. Fixes issue 7539.
compiler: Check for loops in self-referential array types.
https://codereview.appspot.com/76400045/#msg2
Merge branch 'issue7525' of github.com:paranoiacblack/gcc into issue7525

Conflicts:
	gcc/go/gofrontend/expressions.cc