Improve Emscripten support

[Nekto89]

• use compiler=emcc for Emscripten that is available since Conan 2.18.0
• detect compiler.threads (posix and wasm_workers)
• detect wasm64

[Nekto89]

docker run --rm -v C:\dev\cmake-conan:/usr/src/cmake-conan -v C:\dev\test_emscripten_cmake:/usr/src/logs -it emscripten/emsdk:4.0.19 /bin/bash
export PATH=/usr/local/bin:$PATH
apt-get remove cmake
wget -qO- "https://github.com/Kitware/CMake/releases/download/v3.31.6/cmake-3.31.6-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
pip3 install conan==2.22.1
conan profile detect
emcmake cmake -B ~/bld -S /usr/src/cmake-conan/example -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-pthread" -DCMAKE_CXX_FLAGS="-pthread" -DCMAKE_EXE_LINKER_FLAGS="-pthread" -DCMAKE_TOOLCHAIN_FILE=/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=../conan_provider.cmake > /usr/src/logs/log.txt 2>&1
rm -rf ~/bld
emcmake cmake -B ~/bld -S /usr/src/cmake-conan/example -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_CXX_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_EXE_LINKER_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_TOOLCHAIN_FILE=/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=../conan_provider.cmake > /usr/src/logs/log64.txt 2>&1

log.txt
log64.txt

[Nekto89]

docker run --rm -v C:\dev\cmake-conan:/usr/src/cmake-conan -v C:\dev\test_emscripten_cmake:/usr/src/logs -it emscripten/emsdk:4.0.19 /bin/bash
export PATH=/usr/local/bin:$PATH
apt-get remove cmake
wget -qO- "https://github.com/Kitware/CMake/releases/download/v3.31.6/cmake-3.31.6-linux-x86_64.tar.gz" | tar --strip-components=1 -xz -C /usr/local
pip3 install conan==2.22.1
conan profile detect
emcmake cmake -B ~/bld -S /usr/src/cmake-conan/example -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-pthread" -DCMAKE_CXX_FLAGS="-pthread" -DCMAKE_EXE_LINKER_FLAGS="-pthread" -DCMAKE_TOOLCHAIN_FILE=/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=../conan_provider.cmake > /usr/src/logs/log.txt 2>&1
rm -rf ~/bld
emcmake cmake -B ~/bld -S /usr/src/cmake-conan/example -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_CXX_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_EXE_LINKER_FLAGS="-pthread -sMEMORY64=1" -DCMAKE_TOOLCHAIN_FILE=/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=../conan_provider.cmake > /usr/src/logs/log64.txt 2>&1

log.txt log64.txt

conan provider doesn't add CMAKE_TOOLCHAIN_FILE but at least it now properly detects compiler=emcc, compiler.threads=posix and arch=wasm64

[memsharded]

conan provider doesn't add CMAKE_TOOLCHAIN_FILE but at least it now properly detects compiler=emcc, compiler.threads=posix and arch=wasm64

There is a PR open here #712 for this