diff --git a/clang/test/Driver/stdlibxx-isystem.cpp b/clang/test/Driver/stdlibxx-isystem.cpp
--- a/clang/test/Driver/stdlibxx-isystem.cpp
+++ b/clang/test/Driver/stdlibxx-isystem.cpp
@@ -1,53 +1,48 @@
-// Backslash escaping makes matching against the installation directory fail on
-// Windows. Temporarily disable the test there until we add an option to print
-// the installation directory unescaped.
-// UNSUPPORTED: system-windows
-
 // By default, we should search for libc++ next to the driver.
 // RUN: mkdir -p %t/bin
 // RUN: mkdir -p %t/include/c++/v1
 // RUN: %clang -target aarch64-linux-android -ccc-install-dir %t/bin \
-// RUN:   -stdlib=libc++ -fsyntax-only %s -### 2>&1 | \
+// RUN:   -stdlib=libc++ -fsyntax-only %s -###-verbatim | \
 // RUN:   FileCheck -check-prefix=LIBCXX %s
 // RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %t/bin \
-// RUN:   -stdlib=libc++ -fsyntax-only %s -### 2>&1 | \
+// RUN:   -stdlib=libc++ -fsyntax-only %s -###-verbatim | \
 // RUN:   FileCheck -check-prefix=LIBCXX %s
 // LIBCXX: InstalledDir: [[INSTALLDIR:.+$]]
-// LIBCXX: "-internal-isystem" "[[INSTALLDIR]]/../include/c++/v1"
+// LIBCXX: -internal-isystem [[INSTALLDIR]]/../include/c++/v1
 
 // Passing -stdlib++-isystem should suppress the default search.
 // RUN: %clang -target aarch64-linux-android -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -stdlib=libc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=NODEFAULT %s
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=NODEFAULT %s
 // RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -stdlib=libc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=NODEFAULT %s
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=NODEFAULT %s
 // NODEFAULT: InstalledDir: [[INSTALLDIR:.+$]]
-// NODEFAULT-NOT: "-internal-isystem" "[[INSTALLDIR]]/../include/c++/v1"
+// NODEFAULT-NOT: -internal-isystem [[INSTALLDIR]]/../include/c++/v1
 
 // And we should add it as an -internal-isystem.
 // RUN: %clang -target aarch64-linux-android -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -stdlib=libc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=INCPATH %s
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=INCPATH %s
 // RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -stdlib=libc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=INCPATH %s
-// INCPATH: "-internal-isystem" "/tmp/foo" "-internal-isystem" "/tmp/bar"
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=INCPATH %s
+// INCPATH: -internal-isystem /tmp/foo -internal-isystem /tmp/bar
 
 // We shouldn't pass the -stdlib++-isystem to cc1.
 // RUN: %clang -target aarch64-linux-android -ccc-install-dir %t/bin \
-// RUN:   -stdlib++-isystem /tmp -stdlib=libc++ -fsyntax-only %s -### 2>&1 | \
-// RUN:   FileCheck -check-prefix=NOCC1 %s
+// RUN:   -stdlib++-isystem /tmp -stdlib=libc++ -fsyntax-only %s \
+// RUN:   -###-verbatim | FileCheck -check-prefix=NOCC1 %s
 // RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %t/bin \
-// RUN:   -stdlib++-isystem /tmp -stdlib=libc++ -fsyntax-only %s -### 2>&1 | \
-// RUN:   FileCheck -check-prefix=NOCC1 %s
-// NOCC1-NOT: "-stdlib++-isystem" "/tmp"
+// RUN:   -stdlib++-isystem /tmp -stdlib=libc++ -fsyntax-only %s \
+// RUN:   -###-verbatim | FileCheck -check-prefix=NOCC1 %s
+// NOCC1-NOT: -stdlib++-isystem /tmp
 
 // It should respect -nostdinc++.
 // RUN: %clang -target aarch64-linux-android -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -nostdinc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=NOSTDINCXX %s
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=NOSTDINCXX %s
 // RUN: %clang -target x86_64-apple-darwin -ccc-install-dir %t/bin \
 // RUN:   -stdlib++-isystem /tmp/foo -stdlib++-isystem /tmp/bar -nostdinc++ \
-// RUN:   -fsyntax-only %s -### 2>&1 | FileCheck -check-prefix=NOSTDINCXX %s
-// NOSTDINCXX-NOT: "-internal-isystem" "/tmp/foo" "-internal-isystem" "/tmp/bar"
+// RUN:   -fsyntax-only %s -###-verbatim | FileCheck -check-prefix=NOSTDINCXX %s
+// NOSTDINCXX-NOT: -internal-isystem /tmp/foo -internal-isystem /tmp/bar