OString has a std::hash specialisation

Change-Id: Ic406cfe794c45db921b1074e5913db3d2c6e6e89
Reviewed-on: https://gerrit.libreoffice.org/70363
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

include/vcl/opengl/OpenGLContext.hxx

@@ -172,15 +172,7 @@ protected:
     OpenGLCapabilitySwitch maOpenGLCapabilitySwitch;
 
 private:
-    struct ProgramHash
-    {
-        size_t operator()( const OString& aDigest ) const
-        {
-            return static_cast<size_t>( rtl_crc32( 0, aDigest.getStr(), aDigest.getLength() ) );
-        }
-    };
-
-    typedef std::unordered_map< OString, std::shared_ptr<OpenGLProgram>, ProgramHash > ProgramCollection;
+    typedef std::unordered_map< OString, std::shared_ptr<OpenGLProgram> > ProgramCollection;
     ProgramCollection maPrograms;
     OpenGLProgram* mpCurrentProgram;