Fix multiple assigns with newlines

Author: haldun

src/prism.c

@@ -11140,6 +11140,8 @@ static pm_node_t *
 parse_targets_validate(pm_parser_t *parser, pm_node_t *first_target, pm_binding_power_t binding_power) {
     pm_node_t *result = parse_targets(parser, first_target, binding_power);
 
+    while (accept1(parser, PM_TOKEN_NEWLINE));
+
     // Ensure that we have either an = or a ) after the targets.
     if (!match2(parser, PM_TOKEN_EQUAL, PM_TOKEN_PARENTHESIS_RIGHT)) {
         pm_parser_err_node(parser, result, PM_ERR_WRITE_TARGET_UNEXPECTED);

test/prism/fixtures/patterns.txt

@@ -202,3 +202,8 @@ end
 foo => Object[{x:}]
 
 1.then { 1 in ^_1 }
+
+(
+  a,
+  b
+) = c