[Turbofan] Make GenericLowering operate concurrently.

src/compiler/js-graph.cc

Index: src/compiler/js-graph.cc
diff --git a/src/compiler/js-graph.cc b/src/compiler/js-graph.cc
index 8626cd1821473a58283789368de722030a8ff06d..0dfb6a61decd8314b0e65a564ecf95da34a9d4ef 100644
--- a/src/compiler/js-graph.cc
+++ b/src/compiler/js-graph.cc
@@ -31,11 +31,26 @@ Node* JSGraph::ToNumberBuiltinConstant() {
 
 Node* JSGraph::CEntryStubConstant(int result_size, SaveFPRegsMode save_doubles,
                                   ArgvMode argv_mode, bool builtin_exit_frame) {
-  if (save_doubles == kDontSaveFPRegs && argv_mode == kArgvOnStack &&
-      result_size == 1) {
+  if (save_doubles == kDontSaveFPRegs && argv_mode == kArgvOnStack) {
+    DCHECK(result_size >= 1 && result_size <= 3);
+    if (!builtin_exit_frame) {
+      CachedNode key;
+      if (result_size == 1) {
+        key = kCEntryStub1Constant;
+      } else if (result_size == 2) {
+        key = kCEntryStub2Constant;
+      } else {
+        DCHECK(result_size == 3);
+        key = kCEntryStub3Constant;
+      }
+      return CACHED(
+          key, HeapConstant(CEntryStub(isolate(), result_size, save_doubles,
+                                       argv_mode, builtin_exit_frame)
+                                .GetCode()));
+    }
     CachedNode key = builtin_exit_frame
-                         ? kCEntryStubWithBuiltinExitFrameConstant
-                         : kCEntryStubConstant;
+                         ? kCEntryStub1WithBuiltinExitFrameConstant
+                         : kCEntryStub1Constant;
     return CACHED(key,
                   HeapConstant(CEntryStub(isolate(), result_size, save_doubles,
                                           argv_mode, builtin_exit_frame)