shader: Emulate 64-bit integers when not supported

Useful for mobile and Intel Xe devices.

src/video_core/renderer_opengl/gl_device.cpp

@@ -159,6 +159,7 @@ Device::Device() {
     has_debugging_tool_attached = IsDebugToolAttached(extensions);
     has_depth_buffer_float = HasExtension(extensions, "GL_NV_depth_buffer_float");
     has_nv_gpu_shader_5 = GLAD_GL_NV_gpu_shader5;
+    has_shader_int64 = HasExtension(extensions, "GL_ARB_gpu_shader_int64");
     has_amd_shader_half_float = GLAD_GL_AMD_gpu_shader_half_float;
     has_sparse_texture_2 = GLAD_GL_ARB_sparse_texture2;
     warp_size_potentially_larger_than_guest = !is_nvidia && !is_intel;

src/video_core/renderer_opengl/gl_device.h

@@ -124,6 +124,10 @@ public:
         return has_nv_gpu_shader_5;
     }
 
+    bool HasShaderInt64() const {
+        return has_shader_int64;
+    }
+
     bool HasAmdShaderHalfFloat() const {
         return has_amd_shader_half_float;
     }
@@ -172,6 +176,7 @@ private:
     bool use_driver_cache{};
     bool has_depth_buffer_float{};
     bool has_nv_gpu_shader_5{};
+    bool has_shader_int64{};
     bool has_amd_shader_half_float{};
     bool has_sparse_texture_2{};
     bool warp_size_potentially_larger_than_guest{};

src/video_core/renderer_opengl/gl_shader_cache.cpp

@@ -211,7 +211,7 @@ ShaderCache::ShaderCache(RasterizerOpenGL& rasterizer_, Core::Frontend::EmuWindo
       },
       host_info{
           .support_float16 = false,
-          .support_int64 = true,
+          .support_int64 = device.HasShaderInt64(),
       } {
     if (use_asynchronous_shaders) {
         workers = CreateWorkers();