This shader has been rendered nonfunctional due to the removal of the function SampleFontLocation, which was never implemented in VideoCommon. The last reference to SampleFontLocation was located in the OGL video backend. It was removed in this commit: f039149198 (diff-24125a6c968a8aca9cadd977d4b9d68f), where many functions were moved to video common, among other things.
This shader should be removed so it does not confuse users with the error that it causes. Alternatively, it could be rewritten so it is compatible with modern versions of Dolphin. I am not familiar with GLSL, so this is currently beyond my skill set.
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