fix assertion failure when some compile errors happen
fix assertion failure when some compile errors happen

I don't actually know of a test case to trigger this

self-hosted won't have this problem because get_pointer_to_type
will return error.SemanticAnalysisFailed

raulgrell/zig,raulgrell/zig,zig-lang/zig,zig-lang/zig,Dimenus/zig,andrewrk/zig,andrewrk/zig,raulgrell/zig,Dimenus/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig,Dimenus/zig