AppleClang does not support "-ffunction-sections" and "-fdata-sections" CFLAGS when compiling with bitcode

[SahilAshar]

When compiling the 1DS SDK with AppleClang (so compiling and linking the static lib directly in Xcode via the provided CMakeLists.txt), AppleClang throws these errors if the -fembed-bitcode and -fembed-bitcode-marker are passed to CMake as CFLAGS as well.

clang: error: -ffunction-sections is not supported with -fembed-bitcode
clang: error: -fdata-sections is not supported with -fembed-bitcode

Apple requires modern iOS apps to build with bitcode enabled, and the inclusion of the -ffunction-sections and -fdata-sections CFLAGS breaks this requirement. Additionally, on Darwin targets, these flags actually have no effect.

rust-lang/cc-rs#291 and rust-lang/cc-rs#294 both contain some additional information on this issue.