A26-5-1: Address compiler compatibility

Move "rand" definition to the global namespace and import into std
with "using", to better reflect "real" compilers.

Author: lcartey

cpp/common/test/includes/standard-library/cstdlib.h

@@ -7,10 +7,10 @@ namespace std {
 [[noreturn]] void quick_exit(int status) noexcept;
 extern "C++" int atexit(void (*f)(void)) noexcept;
 extern "C++" int at_quick_exit(void (*f)(void)) noexcept;
-extern "C++" long rand() noexcept;
 using ::atof;
 using ::atoi;
 using ::atol;
 using ::atoll;
+using ::rand;
 } // namespace std
 #endif // _GHLIBCPP_CSTDLIB

cpp/common/test/includes/standard-library/stdlib.h

@@ -20,4 +20,6 @@ long int atol(const char *str);
 long long int atoll(const char *str);
 double atof(const char *str);
 
+int rand(void);
+
 #endif // _GHLIBCPP_STDLIB

cpp/common/test/rules/donotuserandforgeneratingpseudorandomnumbers/DoNotUseRandForGeneratingPseudorandomNumbers.expected

@@ -1 +1 @@
-| test.cpp:5:47:5:55 | call to rand | Use of banned function std::rand. |
+| test.cpp:5:47:5:55 | call to rand | Use of banned function rand. |