[qfcc] Support typed compound initializers

Explicitly typed compound initializers are what C uses and allows them
to initialized `auto` vars and even pass through `...`. Not tested yet
other than ensuring existing tests didn't break.

tools/qfcc/include/expr.h

@@ -100,6 +100,7 @@ typedef struct element_s {
 typedef struct element_chain_s {
 	element_t  *head;
 	element_t **tail;
+	const type_t *type;			///< inferred if null
 } element_chain_t;
 
 typedef struct ex_listitem_s {

tools/qfcc/source/expr.c

@@ -150,8 +150,9 @@ get_type (const expr_t *e)
 		case ex_select:
 			internal_error (e, "unexpected expression type");
 		case ex_label:
-		case ex_compound:
 			return nullptr;
+		case ex_compound:
+			return e->compound.type;
 		case ex_bool:
 			if (options.code.progsversion == PROG_ID_VERSION)
 				return &type_float;

tools/qfcc/source/expr_compound.c

@@ -365,6 +365,9 @@ assign_elements (expr_t *local_expr, const expr_t *init,
 expr_t *
 initialized_temp_expr (const type_t *type, const expr_t *expr)
 {
+	if (expr->type == ex_compound && expr->compound.type) {
+		type = expr->compound.type;
+	}
 	expr_t     *block = new_block_expr (0);
 
 	//type = unalias_type (type);

tools/qfcc/source/qc-parse.y

@@ -211,6 +211,7 @@ int yylex (YYSTYPE *yylval, YYLTYPE *yylloc);
 %type	<mut_expr>	opt_init_semi opt_expr comma_expr
 %type   <expr>		expr
 %type	<expr>		compound_init
+%type	<spec>		opt_cast
 %type   <mut_expr>	element_list expr_list
 %type	<designator> designator designator_spec
 %type	<element>	element
@@ -1698,8 +1699,28 @@ var_initializer
 	;
 
 compound_init
-	: '{' element_list optional_comma '}'		{ $$ = $2; }
-	| '{' '}'									{ $$ = 0; }
+	: opt_cast '{' element_list optional_comma '}'
+		{
+			auto type = resolve_type_spec ($1);
+			$3->compound.type = type;
+			$$ = $3;
+		}
+	| opt_cast '{' '}'
+		{
+			auto type = resolve_type_spec ($1);
+			if (type) {
+				auto elements = new_compound_init ();
+				elements->compound.type = type;
+				$$ = elements;
+			} else {
+				$$ = nullptr;
+			}
+		}
+	;
+
+opt_cast
+	: '(' typename ')'					{ $$ = $2; }
+	| /*empty*/							{ $$ = (specifier_t) {}; }
 	;
 
 method_optional_state_expr