RFA: v3 PATCH to add on_quick_exit/quick_exit to std

[Paolo Carlini]

On 02/12/2013 12:26 PM, dominiq@lps.ens.fr wrote:
> The test fails on x86_64-apple-darwin10 with
>
> FAIL: 18_support/quick_exit/quick_exit.cc (test for excess errors)
> Excess errors:
> /opt/gcc/work/libstdc++-v3/testsuite/18_support/quick_exit/quick_exit.cc:36:3: error: 'at_quick_exit' is not a member of 'std'
> /opt/gcc/work/libstdc++-v3/testsuite/18_support/quick_exit/quick_exit.cc:38:3: error: 'quick_exit' is not a member of 'std'
>
> UNRESOLVED: 18_support/quick_exit/quick_exit.cc compilation failed to produce executable
Looks like the configure test isn't strict enough and ends up defining 
the macros when the darwin libc actually doesn't provide the functions. 
Jason may want to review it...

Paolo.