build-style/cmake: set CMAKE_BUILD_TYPE to None

- CMAKE_BUILD_TYPE=Release will force -O3 instead of respecting our
  CFLAGS and CXXFLAGS
- Theoretically, we could patch cmake to always use -O2 instead,
  however, patching will break users' expectation when compiling their
  our code.
- RelWithDebInfo could be another option if it's acceptable to always
  have debug symbol available.
- However, some projects ignore all CFLAGS and CXXFLAGS;
- Some other projects relies on CMAKE_BUILD_TYPE=Release to install to
  correct location and/or disable coverage.
- To get away with -O3, we need patching either ways, let's go with
  CMAKE_BUILD_TYPE=None, and patch all problematic softwares.

common/build-style/cmake.sh

@@ -52,7 +52,7 @@ _EOF
 		cmake_args+=" -DCMAKE_TOOLCHAIN_FILE=cross_${XBPS_CROSS_TRIPLET}.cmake"
 	fi
 	cmake_args+=" -DCMAKE_INSTALL_PREFIX=/usr"
-	cmake_args+=" -DCMAKE_BUILD_TYPE=Release"
+	cmake_args+=" -DCMAKE_BUILD_TYPE=None"
 	cmake_args+=" -DCMAKE_INSTALL_LIBDIR=lib${XBPS_TARGET_WORDSIZE}"
 
 	if [[ $build_helper = *"qemu"* ]]; then