Following the conclusion of the
[RFC](https://discourse.llvm.org/t/rfc-names-for-flang-rt-libraries/84321),
rename Flang's runtime libraries as follows:
* libFortranRuntime.(a|so) to libflang_rt.runtime.(a|so)
* libFortranFloat128Math.a to libflang_rt.quadmath.a
* libCufRuntime_cuda_${CUDAToolkit_VERSION_MAJOR}.(a|so) to
libflang_rt.cuda_${CUDAToolkit_VERSION_MAJOR}.(a|so)
This follows the same naming scheme as Compiler-RT libraries
(`libclang_rt.${component}.(a|so)`). It provides some consistency
between Flang's runtime libraries for current and potential future
library components.
5c8c2b3db5
