Don't thread the local crate number through the session

It's a constant, anyway.

src/comp/middle/trans.rs

@@ -4816,7 +4816,7 @@ fn trans_external_path(&@block_ctxt cx, &ast::def_id did,
 fn lval_generic_fn(&@block_ctxt cx, &ty::ty_param_count_and_ty tpt,
                    &ast::def_id fn_id, ast::node_id id) -> lval_result {
     auto lv;
-    if (cx.fcx.lcx.ccx.sess.get_targ_crate_num() == fn_id._0) {
+    if (fn_id._0 == ast::local_crate) {
         // Internal reference.
         assert (cx.fcx.lcx.ccx.fn_pairs.contains_key(fn_id._1));
         lv = lval_val(cx, cx.fcx.lcx.ccx.fn_pairs.get(fn_id._1));
@@ -4851,7 +4851,7 @@ fn lookup_discriminant(&@local_ctxt lcx, &ast::def_id tid, &ast::def_id vid)
         case (none) {
             // It's an external discriminant that we haven't seen yet.
 
-            assert (lcx.ccx.sess.get_targ_crate_num() != vid._0);
+            assert (vid._0 != ast::local_crate);
             auto sym = decoder::get_symbol(lcx.ccx.sess, vid);
             auto gvar =
                 llvm::LLVMAddGlobal(lcx.ccx.llmod, T_int(), str::buf(sym));

src/comp/middle/ty.rs

@@ -2802,7 +2802,7 @@ fn def_has_ty_params(&ast::def def) -> bool {
 type variant_info = rec(vec[ty::t] args, ty::t ctor_ty, ast::def_id id);
 
 fn tag_variants(&ctxt cx, &ast::def_id id) -> vec[variant_info] {
-    if (cx.sess.get_targ_crate_num() != id._0) {
+    if (ast::local_crate != id._0) {
         ret decoder::get_tag_variants(cx, id);
     }
     auto item = alt (cx.items.find(id._1)) {
@@ -2857,7 +2857,7 @@ fn tag_variant_with_id(&ctxt cx, &ast::def_id tag_id, &ast::def_id variant_id)
 // If the given item is in an external crate, looks up its type and adds it to
 // the type cache. Returns the type parameters and type.
 fn lookup_item_type(ctxt cx, ast::def_id did) -> ty_param_count_and_ty {
-    if (did._0 == cx.sess.get_targ_crate_num()) {
+    if (did._0 == ast::local_crate) {
         // The item is in this crate. The caller should have added it to the
         // type cache already; we simply return it.
 

src/comp/middle/typeck.rs

@@ -521,9 +521,8 @@ mod collect {
         ret tpt;
     }
     fn getter(@ctxt cx, &ast::def_id id) -> ty::ty_param_count_and_ty {
-        if (id._0 != cx.tcx.sess.get_targ_crate_num()) {
+        if (id._0 != ast::local_crate) {
             // This is a type we need to load in from the crate reader.
-
             ret decoder::get_type(cx.tcx, id);
         }
         auto it = cx.tcx.items.find(id._1);