Index: llvm/trunk/test/lit.cfg.py
===================================================================
--- llvm/trunk/test/lit.cfg.py
+++ llvm/trunk/test/lit.cfg.py
@@ -228,6 +228,9 @@
 if have_cxx_shared_library():
     config.available_features.add('cxx-shared-library')
 
+if config.libcxx_used:
+    config.available_features.add('libcxx-used')
+
 # Direct object generation
 if not 'hexagon' in config.target_triple:
     config.available_features.add('object-emission')
Index: llvm/trunk/test/lit.site.cfg.py.in
===================================================================
--- llvm/trunk/test/lit.site.cfg.py.in
+++ llvm/trunk/test/lit.site.cfg.py.in
@@ -44,6 +44,7 @@
 config.llvm_host_triple = '@LLVM_HOST_TRIPLE@'
 config.host_arch = "@HOST_ARCH@"
 config.have_opt_viewer_modules = @LLVM_HAVE_OPT_VIEWER_MODULES@
+config.libcxx_used = @LLVM_LIBCXX_USED@
 
 # Support substitution of the tools_dir with user parameters. This is
 # used when we can't determine the tool dir at configuration time.
Index: llvm/trunk/test/tools/llvm-isel-fuzzer/aarch64-execname-options.ll
===================================================================
--- llvm/trunk/test/tools/llvm-isel-fuzzer/aarch64-execname-options.ll
+++ llvm/trunk/test/tools/llvm-isel-fuzzer/aarch64-execname-options.ll
@@ -3,6 +3,9 @@
 ; REQUIRES: static-libs
 ; REQUIRES: aarch64-registered-target
 
+; The above also applies if the binary is built with libc++.
+; UNSUPPORTED: libcxx-used
+
 ; RUN: echo > %t.input
 
 ; RUN: cp llvm-isel-fuzzer %t.bin--aarch64
Index: llvm/trunk/test/tools/llvm-isel-fuzzer/execname-options.ll
===================================================================
--- llvm/trunk/test/tools/llvm-isel-fuzzer/execname-options.ll
+++ llvm/trunk/test/tools/llvm-isel-fuzzer/execname-options.ll
@@ -2,6 +2,9 @@
 ; without copying the whole lib dir or polluting the build dir.
 ; REQUIRES: static-libs
 
+; The above also applies if the binary is built with libc++.
+; UNSUPPORTED: libcxx-used
+
 ; RUN: echo > %t.input
 
 ; RUN: cp llvm-isel-fuzzer %t.bin--gisel
Index: llvm/trunk/test/tools/llvm-opt-fuzzer/exec-options.ll
===================================================================
--- llvm/trunk/test/tools/llvm-opt-fuzzer/exec-options.ll
+++ llvm/trunk/test/tools/llvm-opt-fuzzer/exec-options.ll
@@ -3,6 +3,9 @@
 ; REQUIRES: static-libs
 ; REQUIRES: x86-registered-target
 
+; The above also applies if the binary is built with libc++.
+; UNSUPPORTED: libcxx-used
+
 ; This test is really flaky on Windows. On Windows, executables and DLLs cannot
 ; be deleted or written while they are loaded. The OS unlocks the file some
 ; time after the process terminates, so if 'rm' runs too quickly, it will fail