[libc++] Remove trailing whitespace from libcxx includes, source, tests and benchmarks

Differential Revision: https://reviews.llvm.org/D132175

libcxx/include/new

@@ -164,7 +164,7 @@ class bad_array_new_length : public bad_alloc {
 public:
   bad_array_new_length() noexcept : bad_alloc("bad array new length") {}
 };
-#endif // defined(_LIBCPP_ABI_VCRUNTIME) && defined(_HAS_EXCEPTIONS) &&_HAS_EXCEPTIONS == 0 
+#endif // defined(_LIBCPP_ABI_VCRUNTIME) && defined(_HAS_EXCEPTIONS) && _HAS_EXCEPTIONS == 0
 
 _LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc();  // not in C++ spec
 

libcxx/utils/ci/run-buildbot

@@ -187,6 +187,9 @@ check-generated-output)
     # Depends on LC_COLLATE set at the top of this script.
     ! grep -rn '[^ -~]' libcxx/include/ || false
 
+    # Reject code with trailing whitespace
+    ! grep -rn '[[:blank:]]$' libcxx/include libcxx/src libcxx/test libcxx/benchmarks || false
+
     # Reject patches that introduce dependency cycles in the headers.
     python3 libcxx/utils/graph_header_deps.py >/dev/null
 ;;