llvm-20: bump upstream release.

Author: javacruft

llvm-20.yaml

@@ -1,6 +1,6 @@
 package:
   name: llvm-20
-  version: "20.1.5"
+  version: "20.1.6"
   epoch: 0
   description: Low-level virtual machine ${{vars.major-version}} - core frameworks
   copyright:
@@ -51,7 +51,7 @@ pipeline:
     with:
       repository: https://github.com/llvm/llvm-project
       tag: llvmorg-${{package.version}}
-      expected-commit: 7b09d7b446383b71b63d429b21ee45ba389c5134
+      expected-commit: 47addd4540b4c393e478ba92bea2589e330c57fb
 
   - runs: |
       ffi_include_dir="$(pkg-config --cflags-only-I libffi | sed 's|^-I||g')"