llvm7-7.0.1-3.13.1

- Add patch Fix-big-endian-miscompile-of-bitcast-zex.patch
  to fix miscompilations with rustc 1.43 that lead to LTO failures
  (bsc#1173202)

- Backport fixes and changes from Factory.  [bsc#1197775]
- Drop RUNPATH from packaged binaries, instead set LD_LIBRARY_PATH
  for building and testing to simulate behavior of actual package.
- BuildRequires: python-rpm-macros to fix Leap 15.3 build.
- Add compiler-rt-Remove-cyclades-inclusion-in-sanitizer.patch:
  Fix build with linux-glibc-devel 5.13.