Dropped Support for Bidirectional Custom Target Definition Emulation
Dropped Support for Bidirectional Custom Target Definition Emulation

as requested in the review and argued that this is only consistent with later LLVM upgrades

aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,graydon/rust