fix Issue 8307 - inconsistent treatment of auto functions

function.dd

@@ -125,27 +125,25 @@ foo() = 3;  // reference returns can be lvalues
 
 $(H4 $(LNAME2 auto-functions, Auto Functions))
 
-        $(P Auto functions have their return type inferred from any
-        $(GLINK2 statement, ReturnStatement)s
-        in the function body.
-        )
+    $(P Auto functions have their return type inferred from any
+        $(GLINK2 statement, ReturnStatement)s in the function body.
+    )
 
-        $(P An auto function is declared without a return type.
+    $(P An auto function is declared without a return type.
         If it does not already have a storage class, use the
         $(D_KEYWORD auto) storage class.
-        )
+    )
 
-        $(P If there are multiple $(I ReturnStatement)s, the types
-        of them must match exactly. If there are no $(I ReturnStatement)s,
-        the return type is inferred to be $(D_KEYWORD void).
-        )
+    $(P If there are multiple $(I ReturnStatement)s, the types
+        of them must be implicitly convertible to a common type.
+        If there are no $(I ReturnStatement)s, the return type is inferred
+        to be $(D_KEYWORD void).
 
----
-auto foo(int i)
-{
-    return i + 3;  // return type is inferred to be int
-}
----
+        ---
+        auto foo(int x) { return x + 3; }          // inferred to be int
+        auto foo(int x) { return x; return 2.5; }  // inferred to be double
+        ---
+    )
 
 $(H4 $(LNAME2 auto-ref-functions, Auto Ref Functions))