[libcxx] [test] Fix MSVC warning C4125 "decimal digit terminates octal escape sequence".

[STL_MSFT]

Summary

Fix MSVC warning C4125 "decimal digit terminates octal escape sequence".

MSVC somewhat justifiably warns when it sees an octal escape immediately followed by a decimal digit, even if the octal escape used the maximum of 3 octal digits. Avoiding this warning while preserving the test's semantics (as viewed by the library) is easy - simply separate the string literal after the octal escape is finished.

[EricWF]

I'm not a fan of the warning, but it seems like a minimally invasive fix.

[EricWF]

r272639.

test/std/re/re.regex/re.regex.construct/awk_oct.pass.cpp

 
 int main()
 {
     using std::regex_constants::awk;
 
     assert(std::regex_match("\4", std::regex("\\4", awk)));
     assert(std::regex_match("\41", std::regex("\\41", awk)));
     assert(std::regex_match("\141", std::regex("\\141", awk)));
-    assert(std::regex_match("\1411", std::regex("\\1411", awk)));
+    assert(std::regex_match("\141" "1", std::regex("\\1411", awk)));
 }

test/std/re/re.submatch/re.submatch.op/compare.pass.cpp

 }
 
 int main()
 {
     test(std::string("123"), std::string("123"));
     test(std::string("1234"), std::string("123"));
     test(std::wstring(L"123"), std::wstring(L"123"));
     test(std::wstring(L"1234"), std::wstring(L"123"));
-    test(std::string("123\00056", 6), std::string("123\00056", 6), false);
-    test(std::wstring(L"123\00056", 6), std::wstring(L"123\00056", 6), false);
+    test(std::string("123\000" "56", 6), std::string("123\000" "56", 6), false);
+    test(std::wstring(L"123\000" L"56", 6), std::wstring(L"123\000" L"56", 6), false);
 }