cleanup old code in vm, free globals

vm.nim

@@ -1,5 +1,4 @@
 import strformat
-#import tables
 
 import chunk
 import config
@@ -37,7 +36,6 @@ proc run*(chunk: Chunk): InterpretResult =
     ip: ptr uint8 = chunk.code[0].unsafeAddr
     stack: Stack[NdValue] = newStack[NdValue](256)
     hadError: bool
-    #globals: Table[string, NdValue]
     globals: Table[NdValue, NdValue]
     frames: Stack[Frame] = newStack[Frame](4)
 
@@ -64,8 +62,7 @@ proc run*(chunk: Chunk): InterpretResult =
     let index = readDU8()
     chunk.constants[index]
   
-  #template frameBottom: int = frames.peek().stackBottom
-  template frameBottom: int = frames[frames.high].stackBottom
+  template frameBottom: int = frames.peek().stackBottom
 
   while true:
     {.computedgoto.} # See https://nim-lang.org/docs/manual.html#pragmas-computedgoto-pragma
@@ -242,6 +239,7 @@ proc run*(chunk: Chunk): InterpretResult =
 
   stack.free()
   frames.free()
+  globals.free()
 
   if hadError:
     irRuntimeError