public final VM_Address alloc(int bytes, boolean isScalar, int allocator, AllocAdvice advice)
public final VM_Address alloc(int bytes, boolean isScalar, int allocator)
  public final VM_Address alloc(int bytes, boolean isScalar, int allocator,				AllocAdvice advice)    throws VM_PragmaInline {    if (VM_Interface.VerifyAssertions)       VM_Interface._assert(bytes == (bytes & (~(BYTES_IN_ADDRESS-1))));    if (allocator == DEFAULT_SPACE && bytes > LOS_SIZE_THRESHOLD) {      return los.alloc(isScalar, bytes);    } else {      switch (allocator) {      case  DEFAULT_SPACE: return ss.alloc(isScalar, bytes);      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();      }    }  }