Handle index expressions' callee IDs correctly

Some code that handles unary and binary exprs' callee IDs was
    forgetting to handle the index expr case (since calls to
    user-defined index operators also have callee IDs). This was
    manifesting as an ICE in trans because when monomorphizing a
    function that had one of these operators in it (an index into a
    dvec, in the test case), the callee ID would be unbound to a type.

    Fixed it. Closes #2631.

src/libsyntax/ast_util.rs

@@ -455,7 +455,7 @@ fn id_visitor(vfn: fn@(node_id)) -> visit::vt<()> {
         visit_expr: fn@(e: @expr) {
             vfn(e.id);
             alt e.node {
-              expr_unary(_, _) | expr_binary(_, _, _) {
+              expr_unary(*) | expr_binary(*) | expr_index(*) {
                 vfn(ast_util::op_expr_callee_id(e));
               }
               _ { /* fallthrough */ }

src/rustc/middle/astencode.rs

@@ -200,7 +200,7 @@ fn visit_ids(item: ast::inlined_item, vfn: fn@(ast::node_id)) {
         visit_expr: fn@(e: @ast::expr) {
             vfn(e.id);
             alt e.node {
-              ast::expr_unary(_, _) | ast::expr_binary(_, _, _) {
+              ast::expr_unary(*) | ast::expr_binary(*) | ast::expr_index(*) {
                 vfn(ast_util::op_expr_callee_id(e));
               }
               _ { /* fallthrough */ }

src/rustc/middle/borrowck/check_loans.rs

@@ -583,7 +583,7 @@ fn check_loans_in_expr(expr: @ast::expr,
                         expr.span,
                         [rval]);
       }
-      ast::expr_unary(_, _)
+      ast::expr_unary(*) | ast::expr_index(*)
       if self.bccx.method_map.contains_key(expr.id) {
         self.check_call(expr,
                         none,

src/rustc/middle/typeck/check/writeback.rs

@@ -103,8 +103,8 @@ fn visit_expr(e: @ast::expr, wbcx: wb_ctxt, v: wb_vt) {
         resolve_type_vars_for_node(wbcx, e.span, alloc_id);
       }
 
-      ast::expr_binary(_, _, _) | ast::expr_unary(_, _) |
+      ast::expr_binary(*) | ast::expr_unary(*) | ast::expr_assign_op(*)
-      ast::expr_assign_op(_, _, _) | ast::expr_index(_, _) {
+        | ast::expr_index(*) {
         maybe_resolve_type_vars_for_node(wbcx, e.span,
                                          ast_util::op_expr_callee_id(e));
       }