Track JS allocations as they arrive with no affection on performance when tracking is switched off

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 8f27374af5f156b9c6e85ef2f6622f4fd0821ec2..f85600f8a9703342d14daeb579b4d43e14b007b1 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -4941,9 +4941,15 @@ void SubStringStub::Generate(MacroAssembler* masm) {
     STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
     STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
     __ testb(rbx, Immediate(kStringEncodingMask));
-    __ j(zero, &two_byte_slice, Label::kNear);
+    // Make long jumps when allocations tracking is on due to
+    // RecordObjectAllocation inside MacroAssembler::Allocate.
+    Label::Distance jump_distance =
+        masm->isolate()->heap_profiler()->is_tracking_allocations()
+        ? Label::kFar
+        : Label::kNear;
+    __ j(zero, &two_byte_slice, jump_distance);
     __ AllocateAsciiSlicedString(rax, rbx, r14, &runtime);
-    __ jmp(&set_slice_header, Label::kNear);
+    __ jmp(&set_slice_header, jump_distance);
     __ bind(&two_byte_slice);
     __ AllocateTwoByteSlicedString(rax, rbx, r14, &runtime);
     __ bind(&set_slice_header);