[Interpreter] Replace BytecodeRegisterAllocator with a simple bump pointer.

test/cctest/interpreter/bytecode_expectations/WithStatement.golden

Index: test/cctest/interpreter/bytecode_expectations/WithStatement.golden
diff --git a/test/cctest/interpreter/bytecode_expectations/WithStatement.golden b/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
index a420624a5aae8ec60362f0f2a828f752f6f9761a..f8dea9a84fc1b5ee2775950c7eb1d0712b3299d8 100644
--- a/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
+++ b/test/cctest/interpreter/bytecode_expectations/WithStatement.golden
@@ -10,16 +10,16 @@ wrap: yes
 snippet: "
   with ({x:42}) { return x; }
 "
-frame size: 3
+frame size: 2
 parameter count: 1
 bytecode array length: 22
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   34 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1), R(1),
                 B(Ldar), R(1),
-                B(ToObject), R(2),
+                B(ToObject), R(1),
                 B(Ldar), R(closure),
-                B(CreateWithContext), R(2), U8(1),
+                B(CreateWithContext), R(1), U8(1),
                 B(PushContext), R(0),
   /*   50 S> */ B(LdaLookupSlot), U8(2),
                 B(PopContext), R(0),