common: Add more robust ZSTD handling. (#7071)

src/video_core/renderer_opengl/gl_shader_disk_cache.cpp

@@ -206,6 +206,10 @@ ShaderDiskCache::LoadPrecompiledFile(FileUtil::IOFile& file, bool compressed) {
     if (compressed) {
         const std::vector<u8> decompressed =
             Common::Compression::DecompressDataZSTD(precompiled_file);
+        if (decompressed.empty()) {
+            LOG_ERROR(Render_OpenGL, "Could not decompress precompiled shader cache.");
+            return std::nullopt;
+        }
         SaveArrayToPrecompiled(decompressed.data(), decompressed.size());
     } else {
         SaveArrayToPrecompiled(precompiled_file.data(), precompiled_file.size());

src/video_core/shader/generator/shader_gen.h

@@ -10,10 +10,11 @@
 
 namespace Pica::Shader::Generator {
 
+// NOTE: Changing the order impacts shader transferable and precompiled cache loading.
 enum ProgramType : u32 {
     VS = 0,
-    GS = 2,
     FS = 1,
+    GS = 2,
 };
 
 enum Attributes {