Preserve for loop expression location after doDecl call

Restore currentLoc and currentExpLoc after the doDecl call in the FOR statement handler to prevent the increment expression from inheriting the initialization location.

Author: karoliineh

src/frontc/cabs2cil.ml

@@ -6864,6 +6864,8 @@ and doStatement (s : A.statement) : chunk =
             FC_EXP e1 -> doExp false e1 ADrop
           | FC_DECL d1 -> (doDecl false false d1, zero, voidType)
         in
+        currentLoc := loc';
+        currentExpLoc := SynthetizeLoc.doLoc eloc';
         (* First instruction (assignment) in for loop initializer has non-synthetic statement location before for loop.
            Its expression location inside for loop parentheses is synthetic.
            All other instructions are fully synthetic. *)