Make separate header files for stack and lexer

include/tree_sitter/parser/stack.h

@@ -0,0 +1,23 @@
+#ifndef TREE_SITTER_PARSER_STACK_H_
+#define TREE_SITTER_PARSER_STACK_H_
+
+#include "tree_sitter/runtime.h"
+
+typedef unsigned short ts_state_id;
+typedef struct {
+    size_t size;
+    struct {
+        ts_tree *node;
+        ts_state_id state;
+    } *entries;
+} ts_stack;
+
+ts_stack ts_stack_make();
+ts_tree * ts_stack_reduce(ts_stack *stack, ts_symbol symbol, size_t immediate_child_count, const int *hidden_symbol_flags, const int *ubiquitous_symbol_flags);
+void ts_stack_shrink(ts_stack *stack, size_t new_size);
+void ts_stack_push(ts_stack *stack, ts_state_id state, ts_tree *node);
+ts_state_id ts_stack_top_state(const ts_stack *stack);
+ts_tree * ts_stack_top_node(const ts_stack *stack);
+size_t ts_stack_right_position(const ts_stack *stack);
+
+#endif