[libc++][test] Fix -Wstring-concatenation warnings

Author: ldionne

libcxx/test/libcxx/utilities/function.objects/unord.hash/murmur2_or_cityhash_ubsan_unsigned_overflow_ignored.pass.cpp

@@ -30,7 +30,7 @@ void test(const void* key, int len) {
 
 int main(int, char**) {
   const std::string TestCases[] = {
-      "abcdaoeuaoeclaoeoaeuaoeuaousaotehu]+}sthoasuthaoesutahoesutaohesutaoeusaoetuhasoetuhaoseutaoseuthaoesutaohes"
+      "abcdaoeuaoeclaoeoaeuaoeuaousaotehu]+}sthoasuthaoesutahoesutaohesutaoeusaoetuhasoetuhaoseutaoseuthaoesutaohes",
       "00000000000000000000000000000000000000000000000000000000000000000000000",
       "1237546895+54+4554985416849484213464984765465464654564565645645646546456546546"
   };

libcxx/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp

@@ -66,8 +66,8 @@ const PathCompareTest CompareTestCases[] =
     {"/foo/bar/", "/foo/bar", 1}, // trailing separator
     {"foo", "/foo", -1}, // if !this->has_root_directory() and p.has_root_directory(), a value less than 0.
     {"/foo", "foo", 1}, //  if this->has_root_directory() and !p.has_root_directory(), a value greater than 0.
-    {"//" LONGA "////" LONGB "/" LONGC "///" LONGD, "//" LONGA "/" LONGB "/" LONGC "/" LONGD, 0},
-    { LONGA "/" LONGB "/" LONGC, LONGA "/" LONGB "/" LONGB, 1}
+    {("//" LONGA "////" LONGB "/" LONGC "///" LONGD), ("//" LONGA "/" LONGB "/" LONGC "/" LONGD), 0},
+    {(LONGA "/" LONGB "/" LONGC), (LONGA "/" LONGB "/" LONGB), 1}
 
 };
 #undef LONGA