[Test] Even more visible libstdc++

```
_ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE10_M_emplaceIJS0_ImS3_EEEES0_INS6_14_Node_iteratorIS4_Lb0ELb0EEEbESt17integral_constantIbLb1EEDpOT_
_ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE10_M_emplaceIJS0_ImSsEEEES0_INS6_14_Node_iteratorIS4_Lb0ELb0EEEbESt17integral_constantIbLb1EEDpOT_
_ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE13_M_rehash_auxEmSt17integral_constantIbLb1EE
```

Which corresponds to `_M_emplace` and `_M_rehash_aux`:
```
std::pair<std::__detail::_Node_iterator<std::pair<unsigned long const, std::optional<std::string> >, false, false>, bool> std::_Hashtable<unsigned long, std::pair<unsigned long const, std::optional<std::string> >, std::allocator<std::pair<unsigned long const, std::optional<std::string> > >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_emplace<std::pair<unsigned long, std::optional<std::string> > >(std::integral_constant<bool, true>, std::pair<unsigned long, std::optional<std::string> >&&)
std::pair<std::__detail::_Node_iterator<std::pair<unsigned long const, std::optional<std::string> >, false, false>, bool> std::_Hashtable<unsigned long, std::pair<unsigned long const, std::optional<std::string> >, std::allocator<std::pair<unsigned long const, std::optional<std::string> > >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_emplace<std::pair<unsigned long, std::string> >(std::integral_constant<bool, true>, std::pair<unsigned long, std::string>&&)
std::_Hashtable<unsigned long, std::pair<unsigned long const, std::optional<std::string> >, std::allocator<std::pair<unsigned long const, std::optional<std::string> > >, std::__detail::_Select1st, std::equal_to<unsigned long>, std::hash<unsigned long>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_rehash_aux(unsigned long, std::integral_constant<bool, true>)
```

Author: bnbarham

test/stdlib/symbol-visibility-linux.test-sh

@@ -509,6 +509,9 @@
 // RUN:             -e _ZNSt6vectorISt8optionalISt4pairINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEbEESaIS9_EE17_M_realloc_insertIJRKS9_EEEvN9__gnu_cxx17__normal_iteratorIPS9_SB_EEDpOT_ \
 // RUN:             -e _ZSt7nullopt \
 // RUN:             -e _ZNSt6vectorISt8optionalISt4pairISsbEESaIS3_EE17_M_realloc_insertIJRKS3_EEEvN9__gnu_cxx17__normal_iteratorIPS3_S5_EEDpOT_ \
+// RUN:             -e _ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE10_M_emplaceIJS0_ImS3_EEEES0_INS6_14_Node_iteratorIS4_Lb0ELb0EEEbESt17integral_constantIbLb1EEDpOT_ \
+// RUN:             -e _ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE10_M_emplaceIJS0_ImSsEEEES0_INS6_14_Node_iteratorIS4_Lb0ELb0EEEbESt17integral_constantIbLb1EEDpOT_ \
+// RUN:             -e _ZNSt10_HashtableImSt4pairIKmSt8optionalISsEESaIS4_ENSt8__detail10_Select1stESt8equal_toImESt4hashImENS6_18_Mod_range_hashingENS6_20_Default_ranged_hashENS6_20_Prime_rehash_policyENS6_17_Hashtable_traitsILb0ELb0ELb1EEEE13_M_rehash_auxEmSt17integral_constantIbLb1EE \
 // RUN:   > %t/swiftRemoteMirror-all.txt
 // RUN: %llvm-nm --defined-only --extern-only --no-weak %platform-dylib-dir/%target-library-name(swiftRemoteMirror) > %t/swiftRemoteMirror-no-weak.txt
 // RUN: diff -u %t/swiftRemoteMirror-all.txt %t/swiftRemoteMirror-no-weak.txt