clang: Prepend trailing '/' to sysroot

This is needed to handle a case where clang
isntall and target sysroot are perilously same

e.g.

sysroot = /mnt/clang/recipe-sysroot
clang install = /mnt/clang/recipe-sysroot-native

in this case it will mistakenly assume that
clang is installed under the same sysroot dir
and it will try to add relative ../lib paths
to linker steps which would then be wrong
since they will become relative to clang
installation and not sysroot

Upstream-Status: Pending
Signed-off-by: Khem Raj <raj.khem@gmail.com>

Author: kraj

clang/lib/Driver/ToolChains/Linux.cpp

@@ -215,7 +215,7 @@ Linux::Linux(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
   Multilibs = GCCInstallation.getMultilibs();
   SelectedMultilibs.assign({GCCInstallation.getMultilib()});
   llvm::Triple::ArchType Arch = Triple.getArch();
-  std::string SysRoot = computeSysRoot();
+  std::string SysRoot = computeSysRoot() + "/";
   ToolChain::path_list &PPaths = getProgramPaths();
 
   Generic_GCC::PushPPaths(PPaths);