intel: Add statistic for Non SSA registers after NIR to BRW

This is going to be useful while we convert the NIR to BRW to produce
SSA definitions.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30496>

src/intel/compiler/brw_def_analysis.cpp

@@ -193,8 +193,8 @@ def_analysis::validate(const fs_visitor *v) const
    return true;
 }
 
-void
-def_analysis::print_stats(const fs_visitor *v) const
+unsigned
+def_analysis::ssa_count() const
 {
    unsigned defs = 0;
 
@@ -203,6 +203,14 @@ def_analysis::print_stats(const fs_visitor *v) const
          ++defs;
    }
 
+   return defs;
+}
+
+void
+def_analysis::print_stats(const fs_visitor *v) const
+{
+   const unsigned defs = ssa_count();
+
    fprintf(stderr, "DEFS: %u registers, %u SSA, %u non-SSA => %.1f SSA\n",
            def_count, defs, def_count - defs,
            100.0f * float(defs) / float(def_count));