I broke the mips build yesterday because it doesn't use
<private/bionic_asm.h> like the other architectures, including mips64.
I want to move mips closer to mips64 to try to avoid this kind of thing
in future.
Change-Id: Idb985587ff355b9e5e765c1f5671dc0144cd2488
Also clean up <signal.h> and revert the hacks that were necessary
for 64-bit in linker/debugger.cpp until now.
Change-Id: I3b0554ca8a49ee1c97cda086ce2c1954ebc11892
