node.h: introduce nd_brace to determine if a hash literal is a keyword

NODE_HASH#nd_brace is a flag that is 1 for `foo({ k: 1 })` and 0 for
`foo(k: 1)`.
nd_alen had been abused for the flag (and the implementation is
completely the same), but an explicit name is better to read.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67266 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

compile.c

@@ -3801,7 +3801,7 @@ compile_keyword_arg(rb_iseq_t *iseq, LINK_ANCHOR *const ret,
 
 	    assert(nd_type(node) == NODE_ARRAY);
 	    if (!key_node) {
-		if (flag && !root_node->nd_alen) *flag |= VM_CALL_KW_SPLAT;
+		if (flag && !root_node->nd_brace) *flag |= VM_CALL_KW_SPLAT;
 		return FALSE;
 	    }
 	    else if (nd_type(key_node) == NODE_LIT && RB_TYPE_P(key_node->nd_lit, T_SYMBOL)) {
@@ -4785,7 +4785,7 @@ check_keyword(const NODE *node)
         node = node->nd_head;
     }
 
-    if (nd_type(node) == NODE_HASH && !node->nd_alen) return TRUE;
+    if (nd_type(node) == NODE_HASH && !node->nd_brace) return TRUE;
     return FALSE;
 }
 

node.c

@@ -557,7 +557,7 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
 	return;
 
       case NODE_HASH:
-	if (!node->nd_alen) {
+	if (!node->nd_brace) {
 	    ANN("keyword arguments");
 	    ANN("format: nd_head");
 	    ANN("example: a: 1, b: 2");
@@ -567,8 +567,8 @@ dump_node(VALUE buf, VALUE indent, int comment, const NODE * node)
 	    ANN("format: { [nd_head] }");
 	    ANN("example: { 1 => 2, 3 => 4 }");
 	}
-	F_CUSTOM1(nd_alen, "keyword arguments or hash literal") {
-	    switch (node->nd_alen) {
+	F_CUSTOM1(nd_brace, "keyword arguments or hash literal") {
+	    switch (node->nd_brace) {
 	      case 0: A("0 (keyword argument)"); break;
 	      case 1: A("1 (hash literal)"); break;
 	    }

node.h

@@ -266,6 +266,8 @@ typedef struct RNode {
 #define nd_orig   u2.id
 #define nd_undef  u2.node
 
+#define nd_brace u2.argc
+
 #define NEW_NODE(t,a0,a1,a2,loc) rb_node_newnode((t),(VALUE)(a0),(VALUE)(a1),(VALUE)(a2),loc)
 
 #define NEW_DEFN(i,a,d,loc) NEW_NODE(NODE_DEFN,0,i,NEW_SCOPE(a,d,loc),loc)