[printing] Improve ScopeInfo printing

Bug: v8:7066
Change-Id: I5aa7e976eee6b197586a656ee2e38b9d429ec07b
Reviewed-on: https://chromium-review.googlesource.com/955587Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51881}

src/globals.h

@@ -866,6 +866,26 @@ enum ScopeType : uint8_t {
   WITH_SCOPE       // The scope introduced by with.
 };
 
+inline std::ostream& operator<<(std::ostream& os, ScopeType type) {
+  switch (type) {
+    case ScopeType::EVAL_SCOPE:
+      return os << "EVAL_SCOPE";
+    case ScopeType::FUNCTION_SCOPE:
+      return os << "FUNCTION_SCOPE";
+    case ScopeType::MODULE_SCOPE:
+      return os << "MODULE_SCOPE";
+    case ScopeType::SCRIPT_SCOPE:
+      return os << "SCRIPT_SCOPE";
+    case ScopeType::CATCH_SCOPE:
+      return os << "CATCH_SCOPE";
+    case ScopeType::BLOCK_SCOPE:
+      return os << "BLOCK_SCOPE";
+    case ScopeType::WITH_SCOPE:
+      return os << "WITH_SCOPE";
+  }
+  UNREACHABLE();
+}
+
 // AllocationSiteMode controls whether allocations are tracked by an allocation
 // site.
 enum AllocationSiteMode {

src/objects-printer.cc

@@ -1169,7 +1169,7 @@ void SharedFunctionInfo::SharedFunctionInfoPrint(std::ostream& os) {  // NOLINT
   os << "\n - formal_parameter_count: " << internal_formal_parameter_count();
   os << "\n - expected_nof_properties: " << expected_nof_properties();
   os << "\n - language_mode: " << language_mode();
-  os << " - code: " << Brief(code());
+  os << "\n - code: " << Brief(code());
   if (HasBytecodeArray()) {
     os << "\n - bytecode_array: " << bytecode_array();
   }

src/objects.cc

@@ -3342,9 +3342,13 @@ void HeapObject::HeapObjectShortPrint(std::ostream& os) {  // NOLINT
     break;
       STRUCT_LIST(MAKE_STRUCT_CASE)
 #undef MAKE_STRUCT_CASE
-    case SCOPE_INFO_TYPE:
-      os << "<ScopeInfo[" << ScopeInfo::cast(this)->length() << "]>";
+    case SCOPE_INFO_TYPE: {
+      ScopeInfo* scope = ScopeInfo::cast(this);
+      os << "<ScopeInfo";
+      if (scope->length()) os << " " << scope->scope_type() << " ";
+      os << "[" << scope->length() << "]>";
       break;
+    }
     case CODE_TYPE: {
       Code* code = Code::cast(this);
       os << "<Code " << Code::Kind2String(code->kind());