rename hir_def -> hir_expand

crates/ra_hir_expand/src/lib.rs

@@ -0,0 +1,11 @@
+//! `ra_hir_def` contains initial "phases" of the compiler. Roughly, everything
+//! before types.
+//!
+//! Note that we are in the process of moving parts of `ra_hir` into
+//! `ra_hir_def`, so this crates doesn't contain a lot at the moment.
+
+pub mod db;
+
+pub mod ast_id_map;
+
+pub mod expand;