Use namespace, to ensure tzname definition is distinct from std time.

Author: MichaelRFairhurst

cpp/cert/test/rules/DCL51-CPP/ObjectReusesReservedName.expected

@@ -1 +1 @@
-| test.cpp:18:7:18:12 | tzname | The variable $@ reuses a reserved standard library name. | test.cpp:18:7:18:12 | tzname | tzname |
+| test.cpp:18:20:18:25 | tzname | The variable $@ reuses a reserved standard library name. | test.cpp:18:20:18:25 | tzname | tzname |

cpp/cert/test/rules/DCL51-CPP/test.cpp

@@ -15,7 +15,7 @@ enum {
 
 // int NULL = 0; // NON_COMPLIANT, but not supported by compilers in practice
 
-char *tzname[2]; // NON_COMPLIANT
+namespace ns { int tzname = 0; } // NON_COMPLIANT
 
 void min() {} // NON_COMPLIANT
 
@@ -48,4 +48,4 @@ void test_lambda(const int y) {
   // Lambda generates a static function called `_FUN` when the lambda is
   // converted to a function pointer
   g([](int x) { return x; }); // COMPLIANT - compiler generated
-}
+}