[turbofan] Add initial support for SOFT deopts.

src/compiler/instruction-selector.cc

Index: src/compiler/instruction-selector.cc
diff --git a/src/compiler/instruction-selector.cc b/src/compiler/instruction-selector.cc
index 6c7cfe6e4344137f6bf1a41f24da81684fdd8d15..b6d8c7b636b194cd5d971ee1f5e6f9a6e6a56836 100644
--- a/src/compiler/instruction-selector.cc
+++ b/src/compiler/instruction-selector.cc
@@ -12,6 +12,7 @@
 #include "src/compiler/pipeline.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/state-values-utils.h"
+#include "src/deoptimizer.h"
 
 namespace v8 {
 namespace internal {
@@ -633,12 +634,9 @@ void InstructionSelector::VisitControl(BasicBlock* block) {
       return VisitReturn(input);
     }
     case BasicBlock::kDeoptimize: {
-      // If the result itself is a return, return its input.
-      Node* value =
-          (input != nullptr && input->opcode() == IrOpcode::kDeoptimize)
-              ? input->InputAt(0)
-              : input;
-      return VisitDeoptimize(value);
+      DeoptimizeKind kind = DeoptimizeKindOf(input->op());
+      Node* value = input->InputAt(0);
+      return VisitDeoptimize(kind, value);
     }
     case BasicBlock::kThrow:
       DCHECK_EQ(IrOpcode::kThrow, input->opcode());
@@ -1406,7 +1404,7 @@ void InstructionSelector::VisitReturn(Node* ret) {
 }
 
 
-void InstructionSelector::VisitDeoptimize(Node* value) {
+void InstructionSelector::VisitDeoptimize(DeoptimizeKind kind, Node* value) {
   OperandGenerator g(this);
 
   FrameStateDescriptor* desc = GetFrameStateDescriptor(value);
@@ -1424,7 +1422,16 @@ void InstructionSelector::VisitDeoptimize(Node* value) {
 
   DCHECK_EQ(args.size(), arg_count);
 
-  Emit(kArchDeoptimize, 0, nullptr, arg_count, &args.front(), 0, nullptr);
+  InstructionCode opcode = kArchDeoptimize;
+  switch (kind) {
+    case DeoptimizeKind::kEager:
+      opcode |= MiscField::encode(Deoptimizer::EAGER);
+      break;
+    case DeoptimizeKind::kSoft:
+      opcode |= MiscField::encode(Deoptimizer::SOFT);
+      break;
+  }
+  Emit(opcode, 0, nullptr, arg_count, &args.front(), 0, nullptr);
 }