Cocoa: Fix half of all key events for Caps Lock

This adds reporting of those Caps Lock key events that cause the lock
state to change.

The full fix involving IOHID is being worked on in #1368.

Related to #1368.
Closes #1373.

README.md

@@ -283,6 +283,7 @@ information on what to include when reporting a bug.
 - [EGL] Added support for `EGL_KHR_get_all_proc_addresses` (#871)
 - [EGL] Added support for `EGL_KHR_context_flush_control`
 - [EGL] Bugfix: The test for `EGL_RGB_BUFFER` was invalid
+- [Cocoa] Bugfix: caps lock was not generating key events
 
 
 ## Contact

src/cocoa_window.m

@@ -235,6 +235,8 @@ static NSUInteger translateKeyToModifierFlag(int key)
         case GLFW_KEY_LEFT_SUPER:
         case GLFW_KEY_RIGHT_SUPER:
             return NSEventModifierFlagCommand;
+        case GLFW_KEY_CAPS_LOCK:
+            return NSEventModifierFlagCapsLock;
     }
 
     return 0;