[MacPorts] #70348: ruby33 @3.3.4: error: use of undeclared identifier 'memory_order_seq_cst' on macOS 10.7-10.9

[MacPorts]

#70348: ruby33 @3.3.4: error: use of undeclared identifier 'memory_order_seq_cst'
on macOS 10.7-10.9
--------------------------------------------+--------------------
 Reporter:  aeiouaeiouaeiouaeiouaeiouaeiou  |      Owner:  (none)
     Type:  defect                          |     Status:  new
 Priority:  Normal                          |  Milestone:
Component:  ports                           |    Version:
 Keywords:  lion, mountainlion, mavericks   |       Port:  ruby33
--------------------------------------------+--------------------
 https://build.macports.org/builders/ports-10.9_x86_64-builder/builds/283727/steps
 /install-port/logs/stdio

 {{{
 In file included from vm.c:514:
 ./vm_insnhelper.c:400:5: warning: implicit declaration of function
 'atomic_signal_fence' is invalid in C99 [-Wimplicit-function-declaration]
     atomic_signal_fence(memory_order_seq_cst);
     ^
 ./vm_insnhelper.c:400:25: error: use of undeclared identifier
 'memory_order_seq_cst'
     atomic_signal_fence(memory_order_seq_cst);
                         ^
 }}}

 Old Clang doesn't understand why C++11 chunks are used in C code.
 Since these chunks are part of
 [https://en.cppreference.com/w/cpp/atomic/memory_order stdatomic.h], every
 Clang version below 700 should be blacklisted.

-- 
Ticket URL: <https://trac.macports.org/ticket/70348>
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