build fails on OSX 10.12

[gabrielschulhof]

To reproduce:

0. Log into test-macstadium-macos10.12-x64-1.
1. git clone https://github.com/nodejs/node
2. cd node
3. ./configure && make

The result:

In file included from ../deps/icu-small/source/common/putil.cpp:68:
In file included from ../deps/icu-small/source/common/umutex.h:24:
In file included from /Library/Developer/CommandLineTools/usr/include/c++/v1/condition_variable:111:
In file included from /Library/Developer/CommandLineTools/usr/include/c++/v1/__mutex_base:17:
/Library/Developer/CommandLineTools/usr/include/c++/v1/__threading_support:156:1: error: unknown type name 'mach_port_t'
mach_port_t __libcpp_thread_get_port();
^
/Library/Developer/CommandLineTools/usr/include/c++/v1/__threading_support:300:1: error: unknown type name 'mach_port_t'
mach_port_t __libcpp_thread_get_port() {
^
/Library/Developer/CommandLineTools/usr/include/c++/v1/__threading_support:301:12: error: use of undeclared identifier 'pthread_mach_thread_np'
    return pthread_mach_thread_np(pthread_self());
           ^
3 errors generated.
make[1]: *** [/Users/root1/gabrielschulhof/node/out/Release/obj.target/icuucx/deps/icu-small/source/common/putil.o] Error 1
make: *** [node] Error 2

master is currently at 668bc11.

[targos]

OSX 10.12 is no longer supported.