[x86][asm] Convert comments from # to // Change-Id: I3aa8035a9748262373409444d74c6d9cf465c7ec
[kernel][x86] Remove arch/x86/64/ subdirectory Zircon only supports x86-64. The historical subdirectory split just makes it harder to find all the code. Change-Id: I7c828660bd1d4d277718aa74f35a3fab5f2333ea