Reduce filesize of the tests on MinGW

This patch removes the workaround applied here
1acfd07 .
MinGW is not tested on Appveyor anymore.

support/appveyor-build.py

@@ -11,15 +11,7 @@
 image = os.environ['APPVEYOR_BUILD_WORKER_IMAGE']
 jobid = os.environ['APPVEYOR_JOB_ID']
 cmake_command = ['cmake', '-DFMT_PEDANTIC=ON', '-DCMAKE_BUILD_TYPE=' + config, '..']
-if build == 'mingw':
-    cmake_command.append('-GMinGW Makefiles')
-    build_command = ['mingw32-make', '-j4']
-    test_command = ['mingw32-make', 'test']
-    # Remove the path to Git bin directory from $PATH because it breaks
-    # MinGW config.
-    path = path.replace(r'C:\Program Files (x86)\Git\bin', '')
-    os.environ['PATH'] = r'C:\MinGW\bin;' + path
-else:
+if build == 'msvc':
     # Add MSBuild 14.0 to PATH as described in
     # http://help.appveyor.com/discussions/problems/2229-v140-not-found-on-vs2105rc.
     os.environ['PATH'] = r'C:\Program Files (x86)\MSBuild\15.0\Bin;' + path

test/CMakeLists.txt

@@ -8,9 +8,6 @@ target_link_libraries(test-main gtest fmt)
 
 function(add_fmt_executable name)
   add_executable(${name} ${ARGN})
-  if (MINGW)
-    target_link_libraries(${name} -static-libgcc -static-libstdc++)
-  endif ()
   # (Wstringop-overflow) - [meta-bug] bogus/missing -Wstringop-overflow warnings
   #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88443
   # Bogus -Wstringop-overflow warning