[qfcc] Set current function for inlined functions

It improves error reporting and is even a solution for what to do with
return statements in inline functions.

tools/qfcc/include/expr.h

@@ -38,6 +38,7 @@
 typedef struct type_s type_t;
 typedef struct expr_s expr_t;
 typedef struct algebra_s algebra_t;
+typedef struct function_s function_t;
 
 /**	\defgroup qfcc_expr Expressions
 	\ingroup qfcc
@@ -404,6 +405,7 @@ typedef struct {
 
 typedef struct {
 	const expr_t *expr;
+	function_t *function;		///< for better reporting in inline functions
 } ex_process_t;
 
 typedef struct expr_s {

tools/qfcc/source/expr_call.c

@@ -279,6 +279,7 @@ build_inline_call (symbol_t *fsym, const type_t *ftype,
 	append_expr (call, expr);
 
 	auto proc = new_process_expr (call);
+	proc->process.function = func;
 
 	return proc;
 }

tools/qfcc/source/expr_process.c

@@ -717,7 +717,12 @@ expr_process (const expr_t *expr, rua_ctx_t *ctx)
 
 	auto proc = funcs[expr->type] (expr, ctx);
 	if (proc && proc->type == ex_process) {
+		auto func = current_func;
+		if (proc->process.function) {
+			current_func = proc->process.function;
+		}
 		proc = expr_process (proc->process.expr, ctx);
+		current_func = func;
 	}
 	return proc;
 }

tools/qfcc/source/function.c

@@ -982,6 +982,7 @@ find_function (const expr_t *fexpr, const expr_t *params)
 			// the call will be inlined, so a new scope is needed every
 			// time
 			sym->metafunc->func = new_function (sym->name, gen->name);
+			sym->metafunc->func->type = sym->type;
 			build_generic_scope (sym, current_symtab, gen, ref_types);
 		}
 		return new_symbol_expr (sym);