[Bug libstdc++/52189] [4.7 regression] Relaxed gthreads check breaks Solaris 8/9 symbol versioning

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52189

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-02-10 11:25:35 UTC ---
This change:

--- baseline_symbols.txt        2012-01-23 19:01:03.590486000 +0100
+++ baseline_symbols.txt.s8g    2012-01-23 19:03:38.063402000 +0100
@@ -2176,0 +2177 @@
+FUNC:_ZSt16__get_once_mutexv@@GLIBCXX_3.4.12
@@ -2209,0 +2211 @@
+FUNC:_ZSt23__get_once_functor_lockv@@GLIBCXX_3.4.11
@@ -2212,0 +2215 @@
+FUNC:_ZSt27__set_once_functor_lock_ptrPSt11unique_lockISt5mutexE@@GLIBCXX_3.4.12
@@ -2649,0 +2653 @@
+OBJECT:16:_ZSt14__once_functor@@GLIBCXX_3.4.11
@@ -2715,2 +2718,0 @@
-OBJECT:16:__emutls_v._ZSt11__once_call@@GLIBCXX_3.4.15
-OBJECT:16:__emutls_v._ZSt15__once_callable@@GLIBCXX_3.4.15

indicates that it was previously using TLS and now isn't (as discussed in PR
52104) so that's what should be fixed to bring the __once_call* symbols back