[asan] Don't use libstdc++ in test

It shouldn't be assumed that libstdc++ is always available even on Linux.
Just let the compiler pick the default

Differential Revision: https://reviews.llvm.org/D150809

compiler-rt/test/asan/TestCases/throw_invoke_test.cpp

@@ -1,5 +1,5 @@
 // RUN: %clangxx_asan %s -o %t && %run %t
-// RUN: %clangxx_asan %s -o %t %linux_static_libstdcplusplus && %run %t
+// RUN: %clangxx_asan %s -o %t -static-libstdc++ && %run %t
 
 // Investigate why it fails with NDK 21.
 // UNSUPPORTED: android

compiler-rt/test/lit.common.cfg.py

@@ -646,14 +646,6 @@ def is_windows_lto_supported():
   config.substitutions.append( ("%xdynamiclib_filename" + postfix, 'lib%xdynamiclib_namespec{}.so'.format(postfix)) )
   config.substitutions.append( ("%xdynamiclib_namespec", '%basename_t.dynamic') )
 
-# Provide a substitution that can be used to tell Clang to use a static libstdc++.
-# The substitution expands to nothing on non Linux platforms.
-# FIXME: This should check the target OS, not the host OS.
-if config.host_os == 'Linux':
-  config.substitutions.append( ("%linux_static_libstdcplusplus", "-stdlib=libstdc++ -static-libstdc++") )
-else:
-  config.substitutions.append( ("%linux_static_libstdcplusplus", "") )
-
 config.default_sanitizer_opts = []
 if config.host_os == 'Darwin':
   # On Darwin, we default to `abort_on_error=1`, which would make tests run