What I'm doing:
1. Run `clang++ -### -c test.cc`
2. Run `clang -cc1 -E <flags from previous command> -o test.E`
3. Run `clang++ -c test.E -o test.o`
I want to speed-up the third step. Since I have done all the
preprocessing stuff, I suggest that there is a more efficient way of
calling clang to compile already preprocessed file. How can I do that?
Thanks in advance.