Exclude non-static members

Exclude non-static members from being marked as `constexpr`.

Author: rvermeulen

change_notes/2024-01-31-fix-fp-a7-1-2.md

@@ -1,2 +1,3 @@
 `A7-1-2` - `VariableMissingConstexpr.ql`:
-    - Fix FP reported in #466. Addresses incorrect assumption that calls to `constexpr` functions are always compile-time evaluated.
+    - Fix FP reported in #466. Addresses incorrect assumption that calls to `constexpr` functions are always compile-time evaluated.
+    - Exclude member that aren't `static`, because they cannot be `constexpr`.

cpp/autosar/src/rules/A7-1-2/VariableMissingConstexpr.ql

@@ -81,5 +81,7 @@ where
   // Not assigned by a user in a constructor
   not exists(ConstructorFieldInit cfi | cfi.getTarget() = v and not cfi.isCompilerGenerated()) and
   // Ignore union members
-  not v.getDeclaringType() instanceof Union
+  not v.getDeclaringType() instanceof Union and
+  // If it is a member, it must be static to be constexpr
+  (v instanceof MemberVariable implies v.isStatic())
 select v, "Variable " + v.getName() + " could be marked 'constexpr'."