public final VM_Address alloc(int bytes, boolean isScalar, int allocator)
public final VM_Address alloc(int bytes, int align, int offset, int allocator)
  public final VM_Address alloc(int bytes, boolean isScalar, int allocator)    throws VM_PragmaInline {    switch (allocator) {    case       RC_SPACE: return rc.alloc(isScalar, bytes, false);    case IMMORTAL_SPACE: return immortal.alloc(isScalar, bytes);    case      LOS_SPACE: return los.alloc(isScalar, bytes);    default:      if (VM_Interface.VerifyAssertions)	VM_Interface.sysFail("No such allocator");      return VM_Address.zero();    }  }