[Flang] Check if two ArrayConstructor's are Equal

This also includes comparing the two ImpliedDo

Details:
- For ArrayConstructor, check if x and y have the same
  elements and type
- For ImpliedDo, check if x and y have the same lower,
  upper, stride and values

Author: Thirumalai-Shaktivel

flang/include/flang/Lower/Support/Utils.h

@@ -545,9 +545,51 @@ class IsEqualEvaluateExpr {
     return isEqual(x.proc(), y.proc()) && isEqual(x.arguments(), y.arguments());
   }
   template <typename A>
+  static bool isEqual(const Fortran::evaluate::ImpliedDo<A> &x,
+                      const Fortran::evaluate::ImpliedDo<A> &y) {
+    using Expr = Fortran::evaluate::Expr<A>;
+    for (const auto &[xValue, yValue] : llvm::zip(x.values(), y.values())) {
+      bool checkValue = Fortran::common::visit(
+          common::visitors{
+              [&](const Expr &v, const Expr &w) { return isEqual(v, w); },
+              [&](const auto &, const auto &) {
+                llvm::report_fatal_error("isEqual is not handled yet for "
+                                         "the element type in ImpliedDo");
+                return false;
+              },
+          },
+          xValue.u, yValue.u);
+      if (!checkValue) {
+        return false;
+      }
+    }
+    return isEqual(x.lower(), y.lower()) && isEqual(x.upper(), y.upper()) &&
+           isEqual(x.stride(), y.stride());
+  }
+  template <typename A>
   static bool isEqual(const Fortran::evaluate::ArrayConstructor<A> &x,
                       const Fortran::evaluate::ArrayConstructor<A> &y) {
-    llvm::report_fatal_error("not implemented");
+    for (const auto &[xValue, yValue] : llvm::zip(x, y)) {
+      using Expr = Fortran::evaluate::Expr<A>;
+      using ImpliedDo = Fortran::evaluate::ImpliedDo<A>;
+      bool checkElement = Fortran::common::visit(
+          common::visitors{
+              [&](const Expr &v, const Expr &w) { return isEqual(v, w); },
+              [&](const ImpliedDo &v, const ImpliedDo &w) {
+                return isEqual(v, w);
+              },
+              [&](const auto &, const auto &) {
+                llvm::report_fatal_error("isEqual is not handled yet for "
+                                         "the element type in ImpliedDo");
+                return false;
+              },
+          },
+          xValue.u, yValue.u);
+      if (!checkElement) {
+        return false;
+      }
+    }
+    return x.GetType() == y.GetType();
   }
   static bool isEqual(const Fortran::evaluate::ImpliedDoIndex &x,
                       const Fortran::evaluate::ImpliedDoIndex &y) {