Stabilize fn-like proc macros in expression, pattern and statement positions

Author: petrochenkov

mini-macro/src/lib.rs

@@ -1,4 +1,4 @@
-#![feature(proc_macro_quote, proc_macro_hygiene)]
+#![feature(proc_macro_quote)]
 #![deny(rust_2018_idioms)]
 // FIXME: Remove this attribute once the weird failure is gone.
 #![allow(unused_extern_crates)]

tests/ui/auxiliary/proc_macro_derive.rs

@@ -1,7 +1,7 @@
 // no-prefer-dynamic
 
 #![crate_type = "proc-macro"]
-#![feature(repr128, proc_macro_hygiene, proc_macro_quote)]
+#![feature(repr128, proc_macro_quote)]
 
 extern crate proc_macro;
 

tests/ui/crashes/ice-3741.rs

@@ -1,7 +1,6 @@
 // aux-build:proc_macro_crash.rs
 // run-pass
 
-#![feature(proc_macro_hygiene)]
 #![warn(clippy::suspicious_else_formatting)]
 
 extern crate proc_macro_crash;