Update rustc bootstrap patch

Author: bjorn3

scripts/setup_rust_fork.sh

@@ -32,11 +32,12 @@ index d95b5b7f17f..00b6f0e3635 100644
 
  [dependencies]
  core = { path = "../core" }
--compiler_builtins = { version = "0.1.39", features = ['rustc-dep-of-std'] }
-+compiler_builtins = { version = "0.1.42", features = ['rustc-dep-of-std', 'no-asm'] }
+-compiler_builtins = { version = "0.1.40", features = ['rustc-dep-of-std'] }
++compiler_builtins = { version = "0.1.43", features = ['rustc-dep-of-std', 'no-asm'] }
 
  [dev-dependencies]
  rand = "0.7"
+ rand_xorshift = "0.2"
 EOF
 
 cat > config.toml <<EOF