Revert "llvmPackages_11: Add `$rsrc/lib` to default cflags"
Revert "llvmPackages_11: Add `$rsrc/lib` to default cflags"

This reverts commit 2000ae54295e601a08ec13ea5057557a30b9a13a.

This was intended as a fix for i686 cross compilation, but it has had
other unforeseen consequences, such as breaking rust-bindgen.

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs