libclc: depend on llvm-native.runtime for the host clang (build-only)

The host build works and staged llvm-native's .dev (static libs + cmake) so
find_package(LLVM) now resolves — but the host clang binaries live in
llvm-native's .runtime subpackage, which libclc didn't pull. The .dev ->
.runtime package link does NOT transitively stage at build time, so libclc
errored 'host clang not found under .../sysroot/usr/bin'.

Move the entire host toolchain to dev-dependencies (build-only; libclc's
shipped artifact is the .bc/.pc files, never clang) and add llvm-native.runtime
explicitly so usr/bin/clang* is staged.

local/recipes/dev/libclc/recipe.toml

@@ -26,16 +26,25 @@ template = "custom"
 # WRONG LLVM (its cmake/libs target Redox, not the host).
 #
 # llvm-native is exactly the missing piece: a native (host) LLVM/Clang/LLD 21
-# build (same redox-2025-10-03 revision as llvm21/clang21) whose .dev package
-# ships usr/lib/cmake/llvm/**, libLLVM*.a and host clang/llvm-* binaries. We
-# depend on it ALONE for the host toolchain — pulling in llvm21.dev too would
-# stage a SECOND, conflicting usr/lib/cmake/llvm (the cross one) into the same
-# sysroot path, and find_package would non-deterministically pick the wrong one.
-dependencies = [
-    "llvm-native",
-]
+# build (same redox-2025-10-03 revision as llvm21/clang21). Its packages split
+# as: main = leftover host tools (diagtool, lli, FileCheck, cc/c++ …);
+# .dev = usr/lib/cmake/llvm/**, host libLLVM*.a + includes (for find_package);
+# .runtime = usr/bin/clang*, usr/bin/lld*, usr/bin/llvm-*, libLLVM*.so
+# (the host CLANG libclc RUNS to compile the OpenCL-C builtins to bitcode).
+#
+# ALL of it is BUILD-ONLY: libclc's shipped artifact is the .bc/.pc files that
+# Mesa consumes at runtime, never clang. So the whole host toolchain goes in
+# dev-dependencies (staged into the build sysroot, NOT pulled into the image).
+# We must include .runtime explicitly — the .dev -> .runtime package link does
+# NOT transitively stage .runtime at build time, so without it the host clang
+# is absent and the build errors "host clang not found". We deliberately do NOT
+# pull llvm21.dev (the Redox-cross LLVM) — it would drop a SECOND, conflicting
+# usr/lib/cmake/llvm into the sysroot and find_package would pick the wrong one.
+dependencies = []
 dev-dependencies = [
+    "llvm-native",
     "llvm-native.dev",
+    "llvm-native.runtime",
 ]
 script = '''
 DYNAMIC_INIT