Refactor get constexpr helper to public in unused variable qll and re…

…move from ql.

cpp/autosar/src/rules/M0-1-3/UnusedLocalVariable.ql

@@ -18,12 +18,6 @@ import cpp
 import codingstandards.cpp.autosar
 import codingstandards.cpp.deadcode.UnusedVariables
 
-/** Gets the constant value of a constexpr/const variable. */
-private string getConstExprValue(Variable v) {
-  result = v.getInitializer().getExpr().getValue() and
-  (v.isConst() or v.isConstexpr())
-}
-
 // This predicate is similar to getUseCount for M0-1-4 except that it also
 // considers static_asserts. This was created to cater for M0-1-3 specifically
 // and hence, doesn't attempt to reuse the M0-1-4 specific predicate

cpp/common/src/codingstandards/cpp/deadcode/UnusedVariables.qll

@@ -152,7 +152,7 @@ predicate maybeACompileTimeTemplateArgument(Variable v) {
 }
 
 /** Gets the constant value of a constexpr/const variable. */
-private string getConstExprValue(Variable v) {
+string getConstExprValue(Variable v) {
   result = v.getInitializer().getExpr().getValue() and
   (v.isConst() or v.isConstexpr())
 }