deps: update V8 to 5.4.500.27

Pick up latest commit from the 5.4-lkgr branch.

deps: edit V8 gitignore to allow trace event copy
deps: update V8 trace event to 315bf1e2d45be7d53346c31cfcc37424a32c30c8
deps: edit V8 gitignore to allow gtest_prod.h copy
deps: update V8 gtest to 6f8a66431cb592dad629028a50b3dd418a408c87

PR-URL: https://github.com/nodejs/node/pull/8317
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/deps/v8/src/unicode.cc b/deps/v8/src/unicode.cc
index de5e36038b..db98be8675 100644
--- a/deps/v8/src/unicode.cc
+++ b/deps/v8/src/unicode.cc
@@ -305,6 +305,20 @@ uchar Utf8::CalculateValue(const byte* str, size_t max_length, size_t* cursor) {
          0x03C82080;
 }
 
+bool Utf8::Validate(const byte* bytes, size_t length) {
+  size_t cursor = 0;
+
+  // Performance optimization: Skip over single-byte values first.
+  while (cursor < length && bytes[cursor] <= kMaxOneByteChar) {
+    ++cursor;
+  }
+
+  while (cursor < length) {
+    uchar c = ValueOf(bytes + cursor, length - cursor, &cursor);
+    if (!IsValidCharacter(c)) return false;
+  }
+  return true;
+}
 
 // Uppercase:            point.category == 'Lu'