Suggest building for the host arch

Author: AlexDenisov

GettingStarted/build-install.md

@@ -28,7 +28,7 @@ $ /Applications/CMake.app/Contents/bin/cmake -GNinja \
  -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_INSTALL_PREFIX=${INSTALLDIR} \
  -DLLVM_ENABLE_ASSERTIONS=ON \
- -DLLVM_TARGETS_TO_BUILD="X86" \
+ -DLLVM_TARGETS_TO_BUILD="host" \
  -DLLVM_ENABLE_PROJECTS="clang;mlir;cir" \
  -DCMAKE_CXX_COMPILER=${CLANG}++ \
  -DCMAKE_C_COMPILER=${CLANG} ../