fix incorrect debug info for empty structs
fix incorrect debug info for empty structs

now all tests pass for llvm master branch

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