Fix highlighting of return types on different lines for abstract functions

If a class name is specified as the return type of an abstract
function and positioned on another line than the `function` keyword,
the class name was not highlighted at all.

This commit highlights such class names as return types.

Author: fabacino

php-mode.el

@@ -15,7 +15,7 @@
 (defconst php-mode-version-number "1.19.0"
   "PHP Mode version number.")
 
-(defconst php-mode-modified "2018-04-08"
+(defconst php-mode-modified "2018-04-23"
   "PHP Mode build date.")
 
 ;; This file is free software; you can redistribute it and/or
@@ -1700,7 +1700,7 @@ a completion list."
 
      ;; Highlight return types in functions and methods.
      ("function.+:\\s-*\\??\\(\\(?:\\sw\\|\\s_\\)+\\)" 1 font-lock-type-face)
-     (")\\s-*:\\s-*\\??\\(\\(?:\\sw\\|\\s_\\)+\\)\\s-*\{" 1 font-lock-type-face)
+     (")\\s-*:\\s-*\\??\\(\\(?:\\sw\\|\\s_\\)+\\)\\s-*\\(?:\{\\|;\\)" 1 font-lock-type-face)
 
      ;; Highlight class names used as nullable type hints
      ("\\?\\(\\(:?\\sw\\|\\s_\\)+\\)\\s-+\\$" 1 font-lock-type-face)

tests/type-hints.php

@@ -125,6 +125,12 @@ public function getNullableObject(
     ): ?stdClass {
     }
 
+    abstract public function getOtherObject(
+    ): stdClass;
+
+    abstract public function getOtherNullableObject(
+    ): ?stdClass;
+
     public function getNsObject(
     ): \path\to\my\Object {
     }

tests/type-hints.php.faces

@@ -343,6 +343,26 @@
  ("(\n    ): ?")
  ("stdClass" . font-lock-type-face)
  (" {\n    }\n\n    ")
+ ("abstract" . php-keyword)
+ (" ")
+ ("public" . php-keyword)
+ (" ")
+ ("function" . php-keyword)
+ (" ")
+ ("getOtherObject" . php-function-name)
+ ("(\n    ): ")
+ ("stdClass" . font-lock-type-face)
+ (";\n\n    ")
+ ("abstract" . php-keyword)
+ (" ")
+ ("public" . php-keyword)
+ (" ")
+ ("function" . php-keyword)
+ (" ")
+ ("getOtherNullableObject" . php-function-name)
+ ("(\n    ): ?")
+ ("stdClass" . font-lock-type-face)
+ (";\n\n    ")
  ("public" . php-keyword)
  (" ")
  ("function" . php-keyword)