[compiler] Initial TurboFan code stubs for abstract relational comparison.

src/runtime/runtime-strings.cc

Index: src/runtime/runtime-strings.cc
diff --git a/src/runtime/runtime-strings.cc b/src/runtime/runtime-strings.cc
index 35e443acdb8f3c2894626250ec7e31552d4eea1c..03b8a08afa09bea3a5936e67eb9ca1fed08abc4f 100644
--- a/src/runtime/runtime-strings.cc
+++ b/src/runtime/runtime-strings.cc
@@ -1145,6 +1145,78 @@ RUNTIME_FUNCTION(Runtime_NewString) {
   return *result;
 }
 
+RUNTIME_FUNCTION(Runtime_StringLessThan) {
+  HandleScope handle_scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
+  switch (String::Compare(x, y)) {
+    case ComparisonResult::kLessThan:
+      return isolate->heap()->true_value();
+    case ComparisonResult::kEqual:
+    case ComparisonResult::kGreaterThan:
+      return isolate->heap()->false_value();
+    case ComparisonResult::kUndefined:
+      break;
+  }
+  UNREACHABLE();
+  return Smi::FromInt(0);
+}
+
+RUNTIME_FUNCTION(Runtime_StringLessThanOrEqual) {
+  HandleScope handle_scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
+  switch (String::Compare(x, y)) {
+    case ComparisonResult::kEqual:
+    case ComparisonResult::kLessThan:
+      return isolate->heap()->true_value();
+    case ComparisonResult::kGreaterThan:
+      return isolate->heap()->false_value();
+    case ComparisonResult::kUndefined:
+      break;
+  }
+  UNREACHABLE();
+  return Smi::FromInt(0);
+}
+
+RUNTIME_FUNCTION(Runtime_StringGreaterThan) {
+  HandleScope handle_scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
+  switch (String::Compare(x, y)) {
+    case ComparisonResult::kGreaterThan:
+      return isolate->heap()->true_value();
+    case ComparisonResult::kEqual:
+    case ComparisonResult::kLessThan:
+      return isolate->heap()->false_value();
+    case ComparisonResult::kUndefined:
+      break;
+  }
+  UNREACHABLE();
+  return Smi::FromInt(0);
+}
+
+RUNTIME_FUNCTION(Runtime_StringGreaterThanOrEqual) {
+  HandleScope handle_scope(isolate);
+  DCHECK_EQ(2, args.length());
+  CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
+  switch (String::Compare(x, y)) {
+    case ComparisonResult::kEqual:
+    case ComparisonResult::kGreaterThan:
+      return isolate->heap()->true_value();
+    case ComparisonResult::kLessThan:
+      return isolate->heap()->false_value();
+    case ComparisonResult::kUndefined:
+      break;
+  }
+  UNREACHABLE();
+  return Smi::FromInt(0);
+}
+
 RUNTIME_FUNCTION(Runtime_StringEqual) {
   HandleScope handle_scope(isolate);
   DCHECK_EQ(2, args.length());