[clang] [test] Fix recently pushed mingw tests in some environments

Account for backslashes in paths in mingw.cpp.

Testing clang with the <triple>-clang form seems to require the
x86 target to be enabled, when the triple is an x86 triple. Just
skip that aspect of the test, since the "clang --target=<triple>"
form should give enough test coverage here.

clang/test/Driver/mingw-sysroot.cpp

@@ -16,7 +16,6 @@
 
 // RUN: rm -rf %T/testroot-custom-triple
 // RUN: mkdir -p %T/testroot-custom-triple/bin
-// RUN: ln -s %clang %T/testroot-custom-triple/bin/x86_64-w64-mingw32foo-clang
 // RUN: ln -s %clang %T/testroot-custom-triple/bin/clang
 // RUN: ln -s %S/Inputs/mingw_ubuntu_posix_tree/usr/x86_64-w64-mingw32 %T/testroot-custom-triple/x86_64-w64-mingw32foo
 
@@ -61,6 +60,5 @@
 // If the user calls clang with a custom literal triple, make sure this maps
 // to sysroots with the matching spelling.
 
-// RUN: %T/testroot-custom-triple/bin/x86_64-w64-mingw32foo-clang -rtlib=compiler-rt -stdlib=libstdc++ --sysroot="" -c -### %s 2>&1 | FileCheck -check-prefix=CHECK_TESTROOT_CUSTOM_TRIPLE %s
 // RUN: %T/testroot-custom-triple/bin/clang --target=x86_64-w64-mingw32foo -rtlib=compiler-rt -stdlib=libstdc++ --sysroot="" -c -### %s 2>&1 | FileCheck -check-prefix=CHECK_TESTROOT_CUSTOM_TRIPLE %s
 // CHECK_TESTROOT_CUSTOM_TRIPLE: "{{[^"]+}}/testroot-custom-triple{{/|\\\\}}x86_64-w64-mingw32foo{{/|\\\\}}include"

clang/test/Driver/mingw.cpp

@@ -36,14 +36,14 @@
 // CHECK_MINGW_OPENSUSE_TREE: "[[BASE:[^"]+]]/Inputs/mingw_opensuse_tree/usr{{/|\\\\}}lib64{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.1.0{{/|\\\\}}include{{/|\\\\}}c++"
 // CHECK_MINGW_OPENSUSE_TREE: "[[BASE]]/Inputs/mingw_opensuse_tree/usr{{/|\\\\}}lib64{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.1.0{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}x86_64-w64-mingw32"
 // CHECK_MINGW_OPENSUSE_TREE: "[[BASE]]/Inputs/mingw_opensuse_tree/usr{{/|\\\\}}lib64{{/|\\\\}}gcc{{/|\\\\}}x86_64-w64-mingw32{{/|\\\\}}5.1.0{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}backward"
-// CHECK_MINGW_OPENSUSE_TREE: "[[BASE]]/Inputs/mingw_opensuse_tree/usr{{/|\\\\}}x86_64-w64-mingw32/sys-root/mingw/include"
+// CHECK_MINGW_OPENSUSE_TREE: "[[BASE]]/Inputs/mingw_opensuse_tree/usr{{/|\\\\}}x86_64-w64-mingw32/sys-root/mingw{{/|\\\\}}include"
 
 
 // RUN: %clang -target x86_64-pc-windows-gnu -rtlib=platform -stdlib=libstdc++ -c -### --sysroot=%S/Inputs/mingw_fedora_tree/usr %s 2>&1 | FileCheck -check-prefix=CHECK_MINGW_FEDORA_TREE %s
-// CHECK_MINGW_FEDORA_TREE: "[[BASE:[^"]+]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw/include/c++"
-// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw/include/c++/x86_64-w64-mingw32ucrt"
-// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw/include/c++/backward"
-// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw/include"
+// CHECK_MINGW_FEDORA_TREE: "[[BASE:[^"]+]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw{{/|\\\\}}include{{/|\\\\}}c++"
+// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}x86_64-w64-mingw32ucrt"
+// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}backward"
+// CHECK_MINGW_FEDORA_TREE: "[[BASE]]/Inputs/mingw_fedora_tree/usr{{/|\\\\}}x86_64-w64-mingw32ucrt/sys-root/mingw{{/|\\\\}}include"
 
 
 // RUN: %clang -target i686-pc-windows-gnu -rtlib=platform -stdlib=libstdc++ -c -### --sysroot=%S/Inputs/mingw_arch_tree/usr %s 2>&1 | FileCheck -check-prefix=CHECK_MINGW_ARCH_TREE %s