intel/compiler: Use FALLTHROUGH

Reported by clang's `-Wimplicit-fallthrough`.

Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34014>

src/intel/compiler/brw_inst.cpp

@@ -483,11 +483,11 @@ brw_inst::components_read(unsigned i) const
    case SHADER_OPCODE_MEMORY_LOAD_LOGICAL:
       if (i == MEMORY_LOGICAL_DATA0)
          return 0;
-      /* fallthrough */
+      FALLTHROUGH;
    case SHADER_OPCODE_MEMORY_STORE_LOGICAL:
       if (i == MEMORY_LOGICAL_DATA1)
          return 0;
-      /* fallthrough */
+      FALLTHROUGH;
    case SHADER_OPCODE_MEMORY_ATOMIC_LOGICAL:
       if (i == MEMORY_LOGICAL_DATA0 || i == MEMORY_LOGICAL_DATA1)
          return src[MEMORY_LOGICAL_COMPONENTS].ud;

src/intel/compiler/brw_lower_logical_sends.cpp

@@ -1393,7 +1393,7 @@ setup_lsc_surface_descriptors(const brw_builder &bld, brw_inst *inst,
    switch (surf_type) {
    case LSC_ADDR_SURFTYPE_BSS:
       inst->send_ex_bso = compiler->extended_bindless_surface_offset;
-      /* fall-through */
+      FALLTHROUGH;
    case LSC_ADDR_SURFTYPE_SS:
       assert(surface.file != BAD_FILE);
       /* We assume that the driver provided the handle in the top 20 bits so
@@ -1882,7 +1882,7 @@ lower_hdc_memory_logical_send(const brw_builder &bld, brw_inst *inst)
       break;
    case LSC_ADDR_SURFTYPE_BSS:
       inst->send_ex_bso = compiler->extended_bindless_surface_offset;
-      /* fall-through */
+      FALLTHROUGH;
    case LSC_ADDR_SURFTYPE_SS:
       desc |= GFX9_BTI_BINDLESS;