Add CHANGELOG_HEADER_STATISTICS for dlang/tools/345

Author: wilzbach

changelog/changelog.ddoc

@@ -33,6 +33,7 @@ CHANGELOG_SEP_HEADER_TEXT_NONEMPTY=$(BR)$(BIG $(RELATIVE_LINK2 bugfix-list, List
 CHANGELOG_SEP_HEADER_TEXT=$(HR)
 CHANGELOG_SEP_TEXT_BUGZILLA=$(BR)$(BIG $(LNAME2 bugfix-list, List of all bug fixes and enhancements in D $(VER):))
 CHANGELOG_SEP_NO_TEXT_BUGZILLA=$(BR)$(BIG List of all bug fixes and enhancements in D $(VER).)
+CHANGELOG_HEADER_STATISTICS=$(DIVC changelog-header-stats, $0)
 CHANGELOG_SOURCE_FILE=
 
 BUGSTITLE_TEXT_HEADER=$(BUGSTITLE $1, $+)