Speed up case folding for 8-bit strings

Source/wtf/text/StringImplTest.cpp

Index: Source/wtf/text/StringImplTest.cpp
diff --git a/Source/wtf/text/StringImplTest.cpp b/Source/wtf/text/StringImplTest.cpp
index f8c8600e3070a79bafc01a7e9efbc499fce8ddbe..0997e77cce7c951934015715a1d69f7f63f284fe 100644
--- a/Source/wtf/text/StringImplTest.cpp
+++ b/Source/wtf/text/StringImplTest.cpp
@@ -37,4 +37,13 @@ TEST(WTF, StringImplCreate8Bit)
     ASSERT_TRUE(testStringImpl->is8Bit());
 }
 
+TEST(WTF, StringImplLatin1CaseFoldTable)
+{
+    LChar symbol = 0xff;
+    while (symbol--) {
+        EXPECT_EQ(WTF::Unicode::foldCase(symbol), StringImpl::latin1CaseFoldTable[symbol]);
+    }
+}
+
+
 } // namespace