Fix initializer problem.

Author: MaxSagebaum

regression-tests/test-results/gcc-13-c++2b/pure2-autodiff.cpp.execution

@@ -18,6 +18,8 @@ diff(direct return) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.0000
 diff(intermediate var) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)
 diff(intermediate passive var) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)
 diff(intermediate untyped) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)
+diff(intermediate default init) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)
+diff(intermediate no init) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)
 diff(while loop) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 8.000000, r_d = 5.000000)
 diff(do while loop) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 8.000000, r_d = 5.000000)
 diff(for loop) at (x = 2.000000, x_d = 1.000000, y = 3.000000, y_d = 2.000000) = (r = 5.000000, r_d = 3.000000)

regression-tests/test-results/pure2-autodiff.cpp

@@ -675,7 +675,7 @@ int i_d {};
     int i {}; 
     r_d = x_d + y_d;
     r = x + y;
-    i_d = 0.0;
+    i_d = {  };
     i = 2;
     static_cast<void>(cpp2::move(i_d));
     static_cast<void>(cpp2::move(i));
@@ -710,7 +710,7 @@ double t_d {};
 
     [[nodiscard]] auto ad_test::intermediate_no_init_diff(cpp2::impl::in<double> x, cpp2::impl::in<double> x_d, cpp2::impl::in<double> y, cpp2::impl::in<double> y_d) -> intermediate_no_init_diff_ret{
                                                                                                                                      double r {0.0};
-                                                                                                                                     double r_d {0.0};r_d = 0.0;
+                                                                                                                                     double r_d {0.0};r_d = {  };
     r = 0.0;
 
     cpp2::impl::deferred_init<double> t_d; 
@@ -726,7 +726,7 @@ double t_d {};
     [[nodiscard]] auto ad_test::while_loop_diff(cpp2::impl::in<double> x, cpp2::impl::in<double> x_d, cpp2::impl::in<double> y, cpp2::impl::in<double> y_d) -> while_loop_diff_ret{
                                                                                                                            double r {0.0};
                                                                                                                            double r_d {0.0};
-int i_d {0.0}; 
+int i_d {}; 
 
     int i {0}; 
     r_d = x_d;
@@ -741,7 +741,7 @@ int i_d {0.0};
     [[nodiscard]] auto ad_test::do_while_loop_diff(cpp2::impl::in<double> x, cpp2::impl::in<double> x_d, cpp2::impl::in<double> y, cpp2::impl::in<double> y_d) -> do_while_loop_diff_ret{
                                                                                                                               double r {0.0};
                                                                                                                               double r_d {0.0};
-int i_d {0.0}; 
+int i_d {}; 
 
     int i {0}; 
     r_d = x_d;
@@ -768,7 +768,7 @@ std::vector<double> v_d {};
     CPP2_UFCS(push_back)(v_d, x_d);
     CPP2_UFCS(push_back)(v, y);
     CPP2_UFCS(push_back)(v_d, y_d);
-    r_d = 0.0;
+    r_d = {  };
     r = 0.0;
 {
 auto t_d_iter{CPP2_UFCS(begin)(cpp2::move(v_d))};

regression-tests/test-results/pure2-autodiff.cpp2.output

@@ -610,7 +610,7 @@ ad_test:/* @autodiff @print */ type =
         i: int = ();
         r_d = x_d + y_d;
         r = x + y;
-        i_d = 0.0;
+        i_d = ();
         i = 2;
         _ = i_d;
         _ = i;
@@ -665,7 +665,7 @@ ad_test:/* @autodiff @print */ type =
             out r_d: double = 0.0, 
         ) = 
     {
-        r_d = 0.0;
+        r_d = ();
         r = 0.0;
         t_d: double;
         t: double;
@@ -686,7 +686,7 @@ ad_test:/* @autodiff @print */ type =
             out r_d: double = 0.0, 
         ) = 
     {
-        i_d: int = 0.0;
+        i_d: int = ();
         i: int = 0;
         r_d = x_d;
         r = x;
@@ -709,7 +709,7 @@ ad_test:/* @autodiff @print */ type =
             out r_d: double = 0.0, 
         ) = 
     {
-        i_d: int = 0.0;
+        i_d: int = ();
         i: int = 0;
         r_d = x_d;
         r = x;
@@ -739,7 +739,7 @@ ad_test:/* @autodiff @print */ type =
         v_d.push_back(x_d);
         v.push_back(y);
         v_d.push_back(y_d);
-        r_d = 0.0;
+        r_d = ();
         r = 0.0;
         (copy t_d_iter: _ = v_d.begin(), )
         for v