Split string capacity test into two parts and mark one part as UNSUPPORTED when using sanitizers.

The test is split such that:
- max_size.pass.cpp tests that string::resize() fails to allocator for max_size
  and max_size -1
- over_max_size.pass.cpp tests that string::resize() throws a length error for
  max_size + 1

The test was split into two because max_size.pass.cpp cannot pass with 
sanitizers but over_max_size.pass.cpp can.


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@221969 91177308-0d34-0410-b5e6-96231b3b80d8

test/strings/basic.string/string.capacity/max_size.pass.cpp

@@ -11,6 +11,13 @@
 
 // size_type max_size() const;
 
+// NOTE: asan and msan will fail for one of two reasons
+// 1. If allocator_may_return_null=0 then they will fail because the allocation
+//    returns null.
+// 2. If allocator_may_return_null=1 then they will fail because the allocation
+//    is too large to succeed.
+// UNSUPPORTED: asan, msan
+
 #include <string>
 #include <cassert>
 
@@ -38,17 +45,6 @@ test2(const S& s)
     assert ( s.size() ==  sz );
 }
 
-template <class S>
-void
-test3(const S& s)
-{
-    S s2(s);
-    const size_t sz = s2.max_size() + 1;
-    try { s2.resize(sz, 'x'); }
-    catch ( const std::length_error & ) { return ; }
-    assert ( false );
-}
-
 template <class S>
 void
 test(const S& s)
@@ -56,7 +52,6 @@ test(const S& s)
     assert(s.max_size() >= s.size());
     test1(s);
     test2(s);
-    test3(s);
 }
 
 int main()