Initial stub of a Makefile and patches for LLVM

Nothing much, but getting some patches from chimera linux that should
work.

patches/llvm/0014-clang-disable-multiarch-layout-on-musl.patch

@@ -0,0 +1,28 @@
+From a131432945a9183642bab22188f03969a3855e40 Mon Sep 17 00:00:00 2001
+From: q66 <q66@chimera-linux.org>
+Date: Sat, 4 Nov 2023 09:08:54 +0100
+Subject: [PATCH 14/29] clang: disable multiarch layout on musl
+
+---
+ clang/lib/Driver/ToolChains/Linux.cpp | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/clang/lib/Driver/ToolChains/Linux.cpp b/clang/lib/Driver/ToolChains/Linux.cpp
+index 0767fe6c5..2ac0139dc 100644
+--- a/clang/lib/Driver/ToolChains/Linux.cpp
++++ b/clang/lib/Driver/ToolChains/Linux.cpp
+@@ -47,6 +47,11 @@ std::string Linux::getMultiarchTriple(const Driver &D,
+   bool IsMipsR6 = TargetTriple.getSubArch() == llvm::Triple::MipsSubArch_r6;
+   bool IsMipsN32Abi = TargetTriple.getEnvironment() == llvm::Triple::GNUABIN32;
+ 
++  /* we are not multiarch */
++  if (TargetTriple.isMusl()) {
++    return "";
++  }
++
+   // For most architectures, just use whatever we have rather than trying to be
+   // clever.
+   switch (TargetTriple.getArch()) {
+-- 
+2.49.0
+