intel/compiler: there are 4 types of fences on gfx >= 12.5

Found by code inspection.

There's an assert later checking that we haven't overflown
this array, so this change probably doesn't matter for any
workload.

Cc: 22.1 <mesa-stable>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16665>

src/intel/compiler/brw_fs_nir.cpp

@@ -4556,7 +4556,7 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       }
 
       unsigned fence_regs_count = 0;
-      fs_reg fence_regs[3] = {};
+      fs_reg fence_regs[4] = {};
 
       const fs_builder ubld = bld.group(8, 0);