Fix build warnings for unused functions

This commit addresses two sources of build errors when using the warning
flag -Werror=unused-function for GCC in the default compiler flags.

The affected functions are not used when building in bootstrap
mode and therefore should be ifdefed out.

No functional changes.

Source/cmake.cxx

@@ -138,6 +138,7 @@ using JsonValueMapType = std::unordered_map<std::string, Json::Value>;
 static bool cmakeCheckStampFile(const std::string& stampName);
 static bool cmakeCheckStampList(const std::string& stampList);
 
+#ifndef CMAKE_BOOTSTRAP
 static void cmWarnUnusedCliWarning(const std::string& variable, int /*unused*/,
                                    void* ctx, const char* /*unused*/,
                                    const cmMakefile* /*unused*/)
@@ -145,6 +146,7 @@ static void cmWarnUnusedCliWarning(const std::string& variable, int /*unused*/,
   cmake* cm = reinterpret_cast<cmake*>(ctx);
   cm->MarkCliAsUsed(variable);
 }
+#endif
 
 cmake::cmake(Role role, cmState::Mode mode)
   : FileTimeCache(cm::make_unique<cmFileTimeCache>())

Source/cmakemain.cxx

@@ -318,6 +318,7 @@ int do_cmake(int ac, char const* const* av)
   return 0;
 }
 
+#ifndef CMAKE_BOOTSTRAP
 int extract_job_number(int& index, char const* current, char const* next,
                        int len_of_flag)
 {
@@ -347,6 +348,7 @@ int extract_job_number(int& index, char const* current, char const* next,
   }
   return jobs;
 }
+#endif
 
 int do_build(int ac, char const* const* av)
 {