RFR: 8224816: Provide os::processor_id() implementation for Mac OS

[Kim Barrett]

> On May 28, 2019, at 4:34 AM, Erik Österlund <erik.osterlund at oracle.com> wrote:
> New webrev:
> http://cr.openjdk.java.net/~eosterlund/8224816/webrev.01/
> 
> Incremental:
> http://cr.openjdk.java.net/~eosterlund/8224816/webrev.00_01/

src/hotspot/os/bsd/os_bsd.cpp
3279       asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );
3315   asm ("cpuid\n\t" : "+a" (eax), "+b" (ebx), "+c" (ecx), "+d" (edx) : );

asm is a GNU extension.  We (mostly) use __asm__ in HotSpot, and
(mostly) avoid using GNU extensions.  (For example, I think we can
still do a linux-x64 build with -std=c++98.)

I don't need a new webrev for that change.