Reapply "Lazy deopt without code patching."

runtime/vm/code_patcher_mips.cc

Index: runtime/vm/code_patcher_mips.cc
diff --git a/runtime/vm/code_patcher_mips.cc b/runtime/vm/code_patcher_mips.cc
index a4d0433a09944eae1a17eb3e4eb000b70f30b76e..3ed9af34da4f6d63ed6c95af3b3ebd461b53aa0e 100644
--- a/runtime/vm/code_patcher_mips.cc
+++ b/runtime/vm/code_patcher_mips.cc
@@ -29,10 +29,8 @@ void CodePatcher::PatchStaticCallAt(uword return_address,
 }
 
 
-void CodePatcher::InsertDeoptimizationCallAt(uword start, uword target) {
-  // The inserted call should not overlap the lazy deopt jump code.
-  ASSERT(start + CallPattern::kDeoptCallLengthInBytes <= target);
-  CallPattern::InsertDeoptCallAt(start, target);
+void CodePatcher::InsertDeoptimizationCallAt(uword start) {
+  UNREACHABLE();
 }