LibJS/Bytecode: Bring back the bytecode optimization pipeline

...minus the EliminateLoads pass, since it was not compatible with the
new bytecode format.

Userland/Libraries/LibJS/CMakeLists.txt

@@ -9,6 +9,11 @@ set(SOURCES
     Bytecode/IdentifierTable.cpp
     Bytecode/Instruction.cpp
     Bytecode/Interpreter.cpp
+    Bytecode/Pass/DumpCFG.cpp
+    Bytecode/Pass/GenerateCFG.cpp
+    Bytecode/Pass/MergeBlocks.cpp
+    Bytecode/Pass/PlaceBlocks.cpp
+    Bytecode/Pass/UnifySameBlocks.cpp
     Bytecode/RegexTable.cpp
     Bytecode/StringTable.cpp
     Console.cpp