parser: Restructure anonymous struct generation to prevent some double borrows
parser: Restructure anonymous struct generation to prevent some double borrows

jdub/rust-bindgen,emilio/rust-bindgen,catdesk/rust-bindgen,jdub/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen,catdesk/rust-bindgen,jdub/rust-bindgen,rust-lang/rust-bindgen,jdub/rust-bindgen,catdesk/rust-bindgen,catdesk/rust-bindgen,emilio/rust-bindgen,rust-lang/rust-bindgen,rust-lang/rust-bindgen,emilio/rust-bindgen