[parser] Extend one_char_strings to all chars < 128

That way we can also cache A-Z, 0-9, _, $ (and all others obviously).

Change-Id: I394001646c80bbabf9b09f66eddc1bef82ae91b3
Reviewed-on: https://chromium-review.googlesource.com/c/1341948
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57606}

src/ast/ast-value-factory.cc

@@ -208,9 +208,9 @@ AstStringConstants::AstStringConstants(Isolate* isolate, uint64_t hash_seed)
 
 AstRawString* AstValueFactory::GetOneByteStringInternal(
     Vector<const uint8_t> literal) {
-  if (literal.length() == 1 && IsInRange(literal[0], 'a', 'z')) {
-    int key = literal[0] - 'a';
-    if (one_character_strings_[key] == nullptr) {
+  if (literal.length() == 1 && literal[0] < kMaxOneCharStringValue) {
+    int key = literal[0];
+    if (V8_UNLIKELY(one_character_strings_[key] == nullptr)) {
       uint32_t hash_field = StringHasher::HashSequentialString<uint8_t>(
           literal.start(), literal.length(), hash_seed_);
       one_character_strings_[key] = GetString(hash_field, true, literal);

src/ast/ast-value-factory.h

@@ -363,7 +363,8 @@ class AstValueFactory {
   const AstConsString* empty_cons_string_;
 
   // Caches one character lowercase strings (for minified code).
-  AstRawString* one_character_strings_[26];
+  static const int kMaxOneCharStringValue = 128;
+  AstRawString* one_character_strings_[kMaxOneCharStringValue];
 
   Zone* zone_;