Add an early arm toolchain

This isn't fully functionnal yet

patches/clang-0002.patch

@@ -0,0 +1,45 @@
+From a6ab1bd3b1a1f1e4eb8b8490dac5f1b5b4b72e6a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Hugo=20Beauz=C3=A9e-Luyssen?= <hugo@beauzee.fr>
+Date: Mon, 2 May 2016 15:58:31 +0200
+Subject: [PATCH] Manually revert 0e2452f3055e2e2cad06a55c5ca9c2be13404781
+
+This re-enables mingw detection
+---
+ lib/Driver/MinGWToolChain.cpp | 14 ++++----------
+ 1 file changed, 4 insertions(+), 10 deletions(-)
+
+diff --git a/lib/Driver/MinGWToolChain.cpp b/lib/Driver/MinGWToolChain.cpp
+index 938440b..a1dc25b 100644
+--- a/lib/Driver/MinGWToolChain.cpp
++++ b/lib/Driver/MinGWToolChain.cpp
+@@ -66,23 +66,17 @@ MinGW::MinGW(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
+     : ToolChain(D, Triple, Args) {
+   getProgramPaths().push_back(getDriver().getInstalledDir());
+ 
+-// In Windows there aren't any standard install locations, we search
+-// for gcc on the PATH. In Linux the base is always /usr.
+-#ifdef LLVM_ON_WIN32
++  // On Windows if there is no sysroot we search for gcc on the PATH.
+   if (getDriver().SysRoot.size())
+     Base = getDriver().SysRoot;
++#ifdef LLVM_ON_WIN32
+   else if (llvm::ErrorOr<std::string> GPPName =
+                llvm::sys::findProgramByName("gcc"))
+     Base = llvm::sys::path::parent_path(
+         llvm::sys::path::parent_path(GPPName.get()));
+-  else
+-    Base = llvm::sys::path::parent_path(getDriver().getInstalledDir());
+-#else
+-  if (getDriver().SysRoot.size())
+-    Base = getDriver().SysRoot;
+-  else
+-    Base = "/usr";
+ #endif
++  if (!Base.size())
++    Base = llvm::sys::path::parent_path(getDriver().getInstalledDir());
+ 
+   Base += llvm::sys::path::get_separator();
+   findGccLibDir();
+-- 
+2.8.1
+