Fix local table space for `*_`

We need to make sure there is enough room in the local table for
repeated `*_` parameters

Co-Authored-By: Matt Valentine-House <matt@eightbitraptor.com>

prism_compile.c

@@ -6360,7 +6360,7 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
         //            ^
         if (parameters_node && parameters_node->rest) {
             if (!(PM_NODE_TYPE_P(parameters_node->rest, PM_IMPLICIT_REST_NODE))) {
-                if (!((pm_rest_parameter_node_t *)parameters_node->rest)->name) {
+                if (!((pm_rest_parameter_node_t *)parameters_node->rest)->name || PM_NODE_FLAG_P(parameters_node->rest, PM_PARAMETER_FLAGS_REPEATED_PARAMETER)) {
                     table_size++;
                 }
             }
@@ -6497,7 +6497,13 @@ pm_compile_node(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *const ret,
                 if (name) {
                     // def foo(a, (b, *c, d), e = 1, *f, g, (h, *i, j),  k:, l: 1, **m, &n)
                     //                               ^^
-                    pm_insert_local_index(name, local_index, index_lookup_table, local_table_for_iseq, scope_node);
+                    if (PM_NODE_FLAG_P(parameters_node->rest, PM_PARAMETER_FLAGS_REPEATED_PARAMETER)) {
+                        ID local = pm_constant_id_lookup(scope_node, name);
+                        local_table_for_iseq->ids[local_index] = local;
+                    }
+                    else {
+                        pm_insert_local_index(name, local_index, index_lookup_table, local_table_for_iseq, scope_node);
+                    }
                 }
                 else {
                     // def foo(a, (b, *c, d), e = 1, *, g, (h, *i, j),  k:, l: 1, **m, &n)

test/ruby/test_compile_prism.rb

@@ -1545,6 +1545,10 @@ a
       CODE
     end
 
+    def test_repeated_splat_underscore
+      assert_prism_eval("def self.m(_, _, _ = 1, _ = 2, *_); end; method(:m).parameters")
+    end
+
     def test_repeated_optional_underscore
       assert_prism_eval("def self.m(a, _, _, _ = 1, _ = 2, b); end; method(:m).parameters")
     end