Rename WXTHREAD_XXX_PRIORITY yo wxPRIORITY_XXX.

This will allow to reuse the same constants for the process priorities in an
upcoming commit.

See #14931.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73405 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/thread.cpp

@@ -442,7 +442,7 @@ public:
         m_thread = thread;
         m_hThread = 0;
         m_state = STATE_NEW;
-        m_priority = WXTHREAD_DEFAULT_PRIORITY;
+        m_priority = wxPRIORITY_DEFAULT;
         m_nRef = 1;
     }
 
@@ -699,7 +699,7 @@ bool wxThreadInternal::Create(wxThread *thread, unsigned int stackSize)
         return false;
     }
 
-    if ( m_priority != WXTHREAD_DEFAULT_PRIORITY )
+    if ( m_priority != wxPRIORITY_DEFAULT )
     {
         SetPriority(m_priority);
     }