message: [vcpkg] Fix build scripts on openSUSE and g++9
  The existing code did not correctly pass `CXX` to cmake.
diff: @@ -51,21 +51,21 @@ function(vcpkg_detect_standard_library)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if !defined(__GLIBCXX__)
  - #error not libstdc++
  + #error \"not libstdc++\"
  #endif
  int main() {}"
  _VCPKG_STANDARD_LIBRARY_LIBSTDCXX)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if !defined(_LIBCPP_VERSION)
  - #error not libc++
  + #error \"not libc++\"
  #endif
  int main() {}"
  _VCPKG_STANDARD_LIBRARY_LIBCXX)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if !defined(_MSVC_STL_VERSION)
  - #error not MSVC stl
  + #error \"not MSVC stl\"
  #endif
  int main() {}"
  _VCPKG_STANDARD_LIBRARY_MSVC_STL)
  @@ -101,7 +101,7 @@ function(vcpkg_detect_std_filesystem)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE >= 9
  - #error libstdc++ after version 9 does not require -lstdc++fs
  + #error \"libstdc++ after version 9 does not require -lstdc++fs\"
  #endif
  int main() {}"
  _VCPKG_REQUIRE_LINK_CXXFS)
  @@ -109,7 +109,7 @@ function(vcpkg_detect_std_filesystem)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if !defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE < 8
  - #error libstdc++ before version 8 doesn't support <filesystem>
  + #error \"libstdc++ before version 8 does not support <filesystem>\"
  #endif
  int main() {}"
  _VCPKG_USE_STD_FILESYSTEM)
  @@ -121,7 +121,7 @@ function(vcpkg_detect_std_filesystem)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if _LIBCPP_VERSION >= 9000
  - #error libc++ after version 9 does not require -lc++fs
  + #error \"libc++ after version 9 does not require -lc++fs\"
  #endif
  int main() {}"
  _VCPKG_REQUIRE_LINK_CXXFS)
  @@ -133,7 +133,7 @@ function(vcpkg_detect_std_filesystem)
  check_cxx_source_compiles(
  "#include <ciso646>
  #if !defined(_MSVC_STL_UPDATE) || _MSVC_STL_UPDATE < 201803
  - #error MSVC STL before 15.7 doesn't support <filesystem>
  + #error \"MSVC STL before 15.7 does not support <filesystem>\"
  #endif
  int main() {}"
  _VCPKG_USE_STD_FILESYSTEM)
  