clang: Update version from 8.0.0 to 9.0.1

1.  https://lists.llvm.org/pipermail/llvm-announce/2019-September/000085.html
2.  https://lists.llvm.org/pipermail/llvm-announce/2019-December/000086.html
3.  https://releases.llvm.org/9.0.0/tools/clang/docs/ReleaseNotes.html

clang.be0

@@ -1,6 +1,6 @@
 #!/usr/bin/env beesh
 
-# BEE_VERSION clang-8.0.0-0
+# BEE_VERSION clang-9.0.1-0
 
 ## this file was created by bee init and should be executed to build a
 ## bee-package. (Additional hints are located at the end of this file.)
@@ -9,7 +9,7 @@
 ## The source URL(s) define the location of the sources that will be
 ## downloaded. Version variables may be used to simplify reuse of this bee-file.
 
-SRCURL[0]="http://llvm.org/releases/${PKGVERSION}/cfe-${PKGVERSION}.src.tar.xz"
+SRCURL[0]="https://github.com/llvm/llvm-project/releases/download/llvmorg-${PKGVERSION}/clang-${PKGVERSION}.src.tar.xz"
 
 ###############################################################################
 ## Add URLs/pathes to patch files to the PATCHURL array.