[turbofan] Induction variable bound analysis.

src/flag-definitions.h

Index: src/flag-definitions.h
diff --git a/src/flag-definitions.h b/src/flag-definitions.h
index b4691219e40430f9bff2e71ee3b54f8c624b155c..a57a1d73328d97f067768481d1405972d7259ecb 100644
--- a/src/flag-definitions.h
+++ b/src/flag-definitions.h
@@ -446,6 +446,7 @@ DEFINE_BOOL(trace_turbo_reduction, false, "trace TurboFan's various reducers")
 DEFINE_BOOL(trace_turbo_trimming, false, "trace TurboFan's graph trimmer")
 DEFINE_BOOL(trace_turbo_jt, false, "trace TurboFan's jump threading")
 DEFINE_BOOL(trace_turbo_ceq, false, "trace TurboFan's control equivalence")
+DEFINE_BOOL(trace_turbo_loop, false, "trace TurboFan's loop optimizations")
 DEFINE_BOOL(turbo_asm, true, "enable TurboFan for asm.js code")
 DEFINE_BOOL(turbo_asm_deoptimization, false,
             "enable deoptimization in TurboFan for asm.js code")
@@ -477,6 +478,7 @@ DEFINE_BOOL(turbo_jt, true, "enable jump threading in TurboFan")
 DEFINE_BOOL(turbo_stress_loop_peeling, false,
             "stress loop peeling optimization")
 DEFINE_BOOL(turbo_loop_peeling, false, "Turbofan loop peeling")
+DEFINE_BOOL(turbo_loop_variable, false, "Turbofan loop variable optimization")
 DEFINE_BOOL(turbo_cf_optimization, true, "optimize control flow in TurboFan")
 DEFINE_BOOL(turbo_frame_elision, true, "elide frames in TurboFan")
 DEFINE_BOOL(turbo_cache_shared_code, true, "cache context-independent code")