[interpreter] Enable OSR for Ignition by default.

This enables the on-stack replacement mechanism from Ignition bytecode
to TurboFan optimized code by default. The runtime profiler is now
allowed to arm OSR points in bytecode.

R=rmcilroy@chromium.org

Review-Url: https://codereview.chromium.org/2432413004
Cr-Commit-Position: refs/heads/master@{#40911}

src/flag-definitions.h

@@ -287,11 +287,10 @@ DEFINE_BOOL(string_slices, true, "use string slices")
 DEFINE_BOOL(ignition, false, "use ignition interpreter")
 DEFINE_BOOL(ignition_staging, false, "use ignition with all staged features")
 DEFINE_IMPLICATION(ignition_staging, ignition)
-DEFINE_IMPLICATION(ignition_staging, ignition_osr)
 DEFINE_STRING(ignition_filter, "*", "filter for ignition interpreter")
 DEFINE_BOOL(ignition_deadcode, true,
             "use ignition dead code elimination optimizer")
-DEFINE_BOOL(ignition_osr, false, "enable support for OSR from ignition code")
+DEFINE_BOOL(ignition_osr, true, "enable support for OSR from ignition code")
 DEFINE_BOOL(ignition_peephole, true, "use ignition peephole optimizer")
 DEFINE_BOOL(ignition_reo, true, "use ignition register equivalence optimizer")
 DEFINE_BOOL(ignition_filter_expression_positions, true,