Fix appveyor breakage due to meson fix. (#904)

* change protobuf appveyor build (remove -Dprotobuf_MSVC_STATIC_RUNTIME=NO)

* clear appveyor cache

* set static/shared crt option for nvcc according to default_library and meson version (for fixed bug)

appveyor.yml

@@ -37,7 +37,7 @@ install:
 - cmd: IF NOT EXIST c:\cache\protobuf\ git clone -b v3.5.1 --single-branch --depth 1 https://github.com/google/protobuf.git
 - cmd: IF NOT EXIST c:\cache\protobuf\ mkdir protobuf\build_msvc
 - cmd: IF NOT EXIST c:\cache\protobuf\ cd protobuf\build_msvc
-- cmd: IF NOT EXIST c:\cache\protobuf\ cmake -G "Visual Studio 15 2017 Win64" -Dprotobuf_BUILD_SHARED_LIBS=NO -Dprotobuf_MSVC_STATIC_RUNTIME=NO -Dprotobuf_BUILD_TESTS=OFF -DCMAKE_INSTALL_PREFIX=c:/cache/protobuf ../cmake
+- cmd: IF NOT EXIST c:\cache\protobuf\ cmake -G "Visual Studio 15 2017 Win64" -Dprotobuf_BUILD_SHARED_LIBS=NO -Dprotobuf_BUILD_TESTS=OFF -DCMAKE_INSTALL_PREFIX=c:/cache/protobuf ../cmake
 - cmd: IF NOT EXIST c:\cache\protobuf\ msbuild INSTALL.vcxproj /p:Configuration=Release /p:Platform=x64 /m
 - cmd: set PATH=c:\cache\protobuf\bin;%PATH%
 - cmd: IF NOT EXIST c:\cache\testnet appveyor DownloadFile http://lczero.org/get_network?sha=7170f639ba1cdc407283b8e52377283e36845b954788c6ada8897937637ef032 -Filename c:\cache\testnet
@@ -48,7 +48,7 @@ install:
 - cmd: IF %GTEST%==true IF NOT EXIST KQvKQ.rtbz curl --remote-name-all https://tablebase.lichess.ovh/tables/standard/3-4-5/K{P,N,R,B,Q}vK{P,N,R,B,Q}.rtb{w,z}
 - cmd: cd C:\projects\lc0
 cache:
-  - C:\cache
+  - C:\cache -> appveyor.yml
   - 'C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v10.0'
   - C:\projects\lc0\subprojects\packagecache
 before_build:

meson.build

@@ -373,7 +373,12 @@ if get_option('build_backends')
     cuda_arguments = ['@EXTRA_ARGS@', '-c', '@INPUT@', '-o', '@OUTPUT@',
                       '-I', meson.current_source_dir() + '/src']
     if host_machine.system() == 'windows'
-      cuda_arguments += ['-Xcompiler', '-MD']
+      # meson bug fixed in v0.51
+      if meson.version().version_compare('<0.51') or get_option('default_library') != 'static'
+        cuda_arguments += ['-Xcompiler', '-MD']
+      else
+        cuda_arguments += ['-Xcompiler', '-MT']
+      endif
     else
       cuda_arguments += ['--std=c++14', '-Xcompiler', '-fPIC']
     endif