make examples work for clang-19 (#28)

* make examples work for clang-19

* follow conventions

content/_index.md

@@ -21,6 +21,7 @@ int main() {
     // Evaluates to 2 * x = 6.28
     double grad_x = __enzyme_autodiff((void*)square, x);
     printf("square'(%f) = %f\n", x,  grad_x);
+    return 0;
 }
 ```
 

content/getting_started/CallingConvention.md

@@ -22,6 +22,7 @@ double __enzyme_autodiffDouble(double (*)(double), double);
 int main() {
   printf("float  d/dx %f\n", __enzyme_autodiffFloat(square<float>, 1.0f));
   printf("double d/dx %f\n", __enzyme_autodiffDouble(square<double>, 1.0));
+  return 0;
 }
 ```
 
@@ -84,6 +85,7 @@ int main() {
                        enzyme_dup  , array, d_array,
                        enzyme_const, size,
                        enzyme_out  , mul);
+  return 0;
 }
 ```
 

content/getting_started/UsingEnzyme.md

@@ -36,6 +36,7 @@ double dsquare(double x) {
 int main() {
     for(double i=1; i<5; i++)
         printf("square(%f)=%f, dsquare(%f)=%f", i, square(i), i, dsquare(i));
+    return 0;
 }
 ```