Replace the old --with-cxx-* configure options with a single --with-gcc-toolchain
that just uses the new toolchain probing logic. This fixes linking with -m32 on
64 bit systems (the /32 dir was not being added to the search).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149651 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/llvm-compilers-check b/utils/llvm-compilers-check
index f7eecfc..623ebc6 100755
--- a/utils/llvm-compilers-check
+++ b/utils/llvm-compilers-check
@@ -347,28 +347,26 @@
 
         # Assume we're building with gcc for now.
         cxxincludes = self.get_includes()
-        cxxroot = cxxincludes[0]
-        cxxarch = os.path.basename(cxxincludes[1])
+        cxxroot = os.path.dirname(cxxincludes[0]) # Remove the version
+        cxxroot = os.path.dirname(cxxroot)        # Remove the c++
+        cxxroot = os.path.dirname(cxxroot)        # Remove the include
 
         configure_flags = dict(
             llvm=dict(debug=["--prefix=" + self.install_prefix,
                              "--with-extra-options=-Werror",
                              "--enable-assertions",
                              "--disable-optimized",
-                             "--with-cxx-include-root=" + cxxroot,
-                             "--with-cxx-include-arch=" + cxxarch],
+                             "--with-gcc-toolchain=" + cxxroot],
                       release=["--prefix=" + self.install_prefix,
                                "--with-extra-options=-Werror",
                                "--enable-optimized",
-                               "--with-cxx-include-root=" + cxxroot,
-                               "--with-cxx-include-arch=" + cxxarch],
+                               "--with-gcc-toolchain=" + cxxroot],
                       paranoid=["--prefix=" + self.install_prefix,
                                 "--with-extra-options=-Werror",
                                 "--enable-assertions",
                                 "--enable-expensive-checks",
                                 "--disable-optimized",
-                                "--with-cxx-include-root=" + cxxroot,
-                                "--with-cxx-include-arch=" + cxxarch]),
+                                "--with-gcc-toolchain=" + cxxroot]),
             dragonegg=dict(debug=[],
                            release=[],
                            paranoid=[]))