Warn/Panic with x86/64 emulation without KVM/HAXM

Previously, running x86_64 without KVM/HAXM will be warned. This
commit extends the warning to include x86, since we cannot reliably
run x86 without KVM/HAXM.

Change-Id: I67e0b8bf615d85c2ced1cff1ac748c7e3f328859
Merge "Warn/Panic with x86/64 emulation without KVM/HAXM" into idea133