Sanity check IMemory access versus underlying mmap

Bug 26877992

Change-Id: Ibbf4b1061e4675e4e96bc944a865b53eaf6984fe

uint32_t BpMemoryHeap::getOffset() const {
    assertMapped();
 return mOffset;
}

uint32_t BpMemoryHeap::getOffset() const {
    assertMapped();
 return mOffset;
}
