added #903 to the test suite

compiler/vm.nim

@@ -448,7 +448,7 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
         let n = src.sons[rc]
         regs[ra].node = n
       else:
-        stackTrace(c, tos, pc, errIndexOutOfBounds)
+        stackTrace(c, tos, pc, errNilAccess)
     of opcWrObj:
       # a.b = c
       decodeBC(rkNode)
@@ -902,6 +902,10 @@ proc rawExecute(c: PCtx, start: int, tos: PStackFrame): TFullReg =
       let rb = instr.regBx - wordExcess - 1
       ensureKind(rkNode)
       regs[ra].node = c.globals.sons[rb]
+    of opcLdGlobalAddr:
+      let rb = instr.regBx - wordExcess - 1
+      ensureKind(rkNodeAddr)
+      regs[ra].nodeAddr = addr(c.globals.sons[rb])
     of opcRepr:
       decodeB(rkNode)
       createStr regs[ra]

compiler/vmdef.nim

@@ -126,6 +126,7 @@ type
     opcLdConst,   # dest = constants[Bx]
     opcAsgnConst, # dest = copy(constants[Bx])
     opcLdGlobal,  # dest = globals[Bx]
+    opcLdGlobalAddr, # dest = addr(globals[Bx])
 
     opcLdImmInt,  # dest = immediate value
     opcNBindSym,

compiler/vmgen.nim

@@ -1614,7 +1614,7 @@ proc genProc(c: PCtx; s: PSym): int =
     c.gABC(body, opcEof, eofInstr.regA)
     c.optimizeJumps(result)
     s.offset = c.prc.maxSlots
-    #if s.name.s == "tupleUnpack":
+    #if s.name.s == "addStuff":
     #  echo renderTree(body)
     #  c.echoCode(result)
     c.prc = oldPrc