LibJS/Bytecode: Don't reparse regular expressions on instantiation

The RegExpLiteral AST node already has the parsed regex::Parser::Result
so let's plumb that over to the bytecode executable instead of reparsing
the regex every time NewRegExp is executed.

~12% speed-up on language/literals/regexp/S7.8.5_A2.1_T2.js in test262.

Userland/Libraries/LibJS/CMakeLists.txt

@@ -15,6 +15,7 @@ set(SOURCES
     Bytecode/Pass/MergeBlocks.cpp
     Bytecode/Pass/PlaceBlocks.cpp
     Bytecode/Pass/UnifySameBlocks.cpp
+    Bytecode/RegexTable.cpp
     Bytecode/StringTable.cpp
     Console.cpp
     Contrib/Test262/$262Object.cpp