Fix prefixing of function return typehints (#163)

Return typehints are now properly resolved and prefixed when necessary.

Author: theofidry

specs/func-declaration/global.php

@@ -112,14 +112,36 @@ class Y {}
     use ArrayIterator;
 
     function foo(
-        Foo $arg0,
-        \Foo $arg1,
-        Foo\Bar $arg2,
-        \Foo\Bar $arg3,
-        ArrayIterator $arg4,
-        \ArrayIterator $arg5,
-        X\Y $arg6,
-        \X\Y $arg7
+        string $arg0,
+        ?string $arg1,
+        ?string $arg2 = null,
+        
+        Foo $arg3,
+        ?Foo $arg4,
+        Foo $arg5 = null,
+        
+        \Foo $arg6,
+        ?\Foo $arg7,
+        \Foo $arg8 = null,
+        
+        Foo\Bar $arg9,
+        ?Foo\Bar $arg10,
+        Foo\Bar $arg11 = null,
+        
+        \Foo\Bar $arg7,
+        ?\Foo\Bar $arg12,
+        \Foo\Bar $arg13 = null,
+        
+        ArrayIterator $arg14,
+        ?ArrayIterator $arg15,
+        ?ArrayIterator $arg16 = null,
+        
+        \ArrayIterator $arg17,
+        ?\ArrayIterator $arg18,
+        \ArrayIterator $arg19 = null,
+        
+        X\Y $arg20,
+        \X\Y $arg21
     ) {}
 }
 
@@ -146,7 +168,7 @@ class_alias('Humbug\\X\\Y', 'X\\Y', \false);
 
 use Humbug\Foo;
 use ArrayIterator;
-function foo(\Humbug\Foo $arg0, \Humbug\Foo $arg1, \Humbug\Foo\Bar $arg2, \Humbug\Foo\Bar $arg3, \ArrayIterator $arg4, \ArrayIterator $arg5, \Humbug\X\Y $arg6, \Humbug\X\Y $arg7)
+function foo(string $arg0, ?string $arg1, ?string $arg2 = null, \Humbug\Foo $arg3, ?\Humbug\Foo $arg4, \Humbug\Foo $arg5 = null, \Humbug\Foo $arg6, ?\Humbug\Foo $arg7, \Humbug\Foo $arg8 = null, \Humbug\Foo\Bar $arg9, ?\Humbug\Foo\Bar $arg10, \Humbug\Foo\Bar $arg11 = null, \Humbug\Foo\Bar $arg7, ?\Humbug\Foo\Bar $arg12, \Humbug\Foo\Bar $arg13 = null, \ArrayIterator $arg14, ?\ArrayIterator $arg15, ?\ArrayIterator $arg16 = null, \ArrayIterator $arg17, ?\ArrayIterator $arg18, \ArrayIterator $arg19 = null, \Humbug\X\Y $arg20, \Humbug\X\Y $arg21)
 {
 }
 
@@ -182,7 +204,6 @@ class Y {}
     use ArrayIterator;
     
     function foo(): void {}
-    function foo(): null {}
     
     function foo(): bool {}
     function foo(): ?bool {}
@@ -246,9 +267,6 @@ class_alias('Humbug\\X\\Y', 'X\\Y', \false);
 function foo() : void
 {
 }
-function foo() : null
-{
-}
 function foo() : bool
 {
 }
@@ -291,40 +309,40 @@ function foo() : callable
 function foo() : ?callable
 {
 }
-function foo() : Foo
+function foo() : \Humbug\Foo
 {
 }
-function foo() : \Foo
+function foo() : \Humbug\Foo
 {
 }
-function foo() : ?Foo
+function foo() : ?\Humbug\Foo
 {
 }
-function foo() : ?\Foo
+function foo() : ?\Humbug\Foo
 {
 }
-function foo() : ArrayIterator
+function foo() : \ArrayIterator
 {
 }
 function foo() : \ArrayIterator
 {
 }
-function foo() : ?ArrayIterator
+function foo() : ?\ArrayIterator
 {
 }
 function foo() : ?\ArrayIterator
 {
 }
-function foo() : X\Y
+function foo() : \Humbug\X\Y
 {
 }
-function foo() : \X\Y
+function foo() : \Humbug\X\Y
 {
 }
-function foo() : ?X\Y
+function foo() : ?\Humbug\X\Y
 {
 }
-function foo() : ?\X\Y
+function foo() : ?\Humbug\X\Y
 {
 }