Only strip files under the bin directory

[yamt]

Stripping other files (eg. *.a) doesn't seem the original intention and it sometimes has ill effects like breaking archive TOC.

[TerrorJack]

Another possible approach would be adding -DCMAKE_EXE_LINKER_FLAGS="-s" to the LLVM configure step, so the linker produces stripped executables directly and we can get rid of the strip logic altogether.

[sbc100]

Another possible approach would be adding -DCMAKE_EXE_LINKER_FLAGS="-s" to the LLVM configure step, so the linker produces stripped executables directly and we can get rid of the strip logic altogether.

Performing the stripped explicitly after the build feels more robust/obvious and makes sense to me from my old debian maintainer days.