Finish Chapter 14

Implements code chunks, a couple of basic opcodes, constants, and
basic execution of those opcodes.

Signed-off-by: Daniel Henry <iamdanhenry@gmail.com>

include/chunk.h

@@ -0,0 +1,25 @@
+#ifndef clox_chunk_h
+#define clox_chunk_h
+
+#include "common.h"
+#include "value.h"
+
+typedef enum {
+  OP_CONSTANT,
+  OP_RETURN,
+} OpCode;
+
+typedef struct {
+  int count;
+  int capacity;
+  uint8_t *code;
+  int *lines;
+  ValueArray constants;
+} Chunk;
+
+void initChunk(Chunk *chunk);
+void freeChunk(Chunk *chunk);
+void writeChunk(Chunk *chunk, uint8_t byte, int line);
+int addConstant(Chunk *chunk, Value value);
+
+#endif /* clox_chunk_h */