Fix struct with array of struct with field that points to first struct.

Fix struct with array of struct with field that points to first struct.
Don't crash converting an untyped complex constant to an integer type.
Don't crash on unsafe.Sizeof of erroneous type.
Don't crash on method expression of erroneous type.
Don't crash when sink and global var are initialized from type guard.
Don't crash initializing erroneous slice.
Don't crash on erroneous method of type seen before definition.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@170301 138bc75d-0d04-0410-961f-82ee72b054a4