Revert "Disable usage of -std=libc++"

This reverts commit 7d6442f67d.

benchmarklib/Makefile

@@ -16,7 +16,7 @@ impl:
 	# if [[ -f CMakeCache.txt ]]; then rm CMakeCache.txt; fi
 	dpkg -i boost/pkg/*.deb
 	pushd benchmarklib && \
-	CXX=$$(which c++) cmake -DNO_AUTO_USE_LIBCPP_CLANG=1 -DSTATIC=1 -DBOOST_ROOT=/opt/cppse/build/boost -DCMAKE_INSTALL_PREFIX=$$PWD/benchmarklib_out . && \
+	CXX=$$(which c++) cmake -DSTATIC=1 -DBOOST_ROOT=/opt/cppse/build/boost -DCMAKE_INSTALL_PREFIX=$$PWD/benchmarklib_out . && \
 	make -j $$(nproc) && \
 	make install
 

boost/Makefile

@@ -16,8 +16,7 @@ impl:
 	mkdir -p target && \
 	CXX=$$(which c++) ./bootstrap.sh --prefix=$$PWD/target/ --with-toolset=clang && \
 	./b2 clean && \
-	./b2 --prefix=$$PWD/target/ toolset=clang cxxflags="-D_GLIBCXX_USE_CXX11_ABI=0 -std=c++17" | true
-#	./b2 --prefix=$$PWD/target/ toolset=clang cxxflags="-D_GLIBCXX_USE_CXX11_ABI=0 -stdlib=libc++ -std=c++17" linkflags="-stdlib=libc++" || true
+	./b2 --prefix=$$PWD/target/ toolset=clang cxxflags="-D_GLIBCXX_USE_CXX11_ABI=0 -stdlib=libc++ -std=c++17" linkflags="-stdlib=libc++" || true
 	#./b2 --prefix=$$PWD/target/ toolset=clang || true
 	# ^ ||true because with clang I saw a few libraries not compile correctly, we can ignore those.
 	#./b2 --with-program_options --prefix=$$PWD/target/ toolset=clang cxxflags="-stdlib=libc++ -std=c++17" linkflags="-stdlib=libc++"

caf/Makefile

@@ -27,7 +27,6 @@ impl:
 		-DCAF_BUILD_STATIC_ONLY=yes \
 		-DCAF_NO_EXAMPLES=yes \
 		-DCAF_NO_UNIT_TESTS=yes \
-		-DCAF_NO_AUTO_LIBCPP=yes \
 		.. && \
 	make -j $$(nproc) && \
 	make install