Handle missing locale in test on more platforms (#2219)

* Add myself to AUTHORS and CONTRIBUTORS

* Improve accuracy of locale support check

It's much easier to list the two platforms libstdc++ does support
locale manipulation on than to try to exhaustively list the myriad
platforms where it does not.

AUTHORS

diff --git a/AUTHORS b/AUTHORS
index 082422c..ab26bb3 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -10,6 +10,7 @@
 
 Albert Pretorius <pretoalb@gmail.com>
 Alex Steele <steeleal123@gmail.com>
+Alyssa Ross <hi@alyssa.is>
 Andriy Berestovskyy <berestovskyy@gmail.com>
 Arne Beer <arne@twobeer.de>
 Benjamin King <kingbenja5@gmail.com>

CONTRIBUTORS

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index f22a988..88c3b1b 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -25,6 +25,7 @@
 Abhina Sreeskantharajan <abhina.sreeskantharajan@ibm.com>
 Albert Pretorius <pretoalb@gmail.com>
 Alex Steele <steelal123@gmail.com>
+Alyssa Ross <hi@alyssa.is>
 Andriy Berestovskyy <berestovskyy@gmail.com>
 Arne Beer <arne@twobeer.de>
 Bátor Tallér <bator.taller@shapr3d.com>

test/locale_impermeability_test.cc

diff --git a/test/locale_impermeability_test.cc b/test/locale_impermeability_test.cc
index 0776fe6..98982a6 100644
--- a/test/locale_impermeability_test.cc
+++ b/test/locale_impermeability_test.cc
@@ -10,9 +10,10 @@
 
 namespace {
 void BM_ostream(benchmark::State& state) {
-#if !defined(__MINGW64__) || defined(__clang__)
-  // GCC-based versions of MINGW64 do not support locale manipulations,
-  // don't run the test under them.
+#if !defined(__GLIBCXX__) || defined(__GLIBC__) || defined(__DragonFly__)
+  // libstdc++ only supports locale manipulations on GNU and
+  // DragonflyBSD platforms at the time of writing, don't run the test
+  // on other platforms when using libstdc++.
   std::locale::global(std::locale("en_US.UTF-8"));
 #endif
   while (state.KeepRunning()) {