LibJS/Bytecode: Make primitive bigints be constants

Instead of emitting a NewBigInt instruction to construct a primitive
bigint from a parsed literal, we now instantiate the BigInt on the heap
during codegen.

Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp

@@ -279,7 +279,7 @@ Bytecode::CodeGenerationErrorOr<Optional<Bytecode::Operand>> NullLiteral::genera
     return generator.add_constant(js_null());
 }
 
-Bytecode::CodeGenerationErrorOr<Optional<Bytecode::Operand>> BigIntLiteral::generate_bytecode(Bytecode::Generator& generator, Optional<Bytecode::Operand> preferred_dst) const
+Bytecode::CodeGenerationErrorOr<Optional<Bytecode::Operand>> BigIntLiteral::generate_bytecode(Bytecode::Generator& generator, [[maybe_unused]] Optional<Bytecode::Operand> preferred_dst) const
 {
     Bytecode::Generator::SourceLocationScope scope(generator, *this);
     // 1. Return the NumericValue of NumericLiteral as defined in 12.8.3.
@@ -293,10 +293,7 @@ Bytecode::CodeGenerationErrorOr<Optional<Bytecode::Operand>> BigIntLiteral::gene
             return MUST(Crypto::SignedBigInteger::from_base(2, m_value.substring(2, m_value.length() - 3)));
         return MUST(Crypto::SignedBigInteger::from_base(10, m_value.substring(0, m_value.length() - 1)));
     }();
-
-    auto dst = choose_dst(generator, preferred_dst);
-    generator.emit<Bytecode::Op::NewBigInt>(dst, integer);
-    return dst;
+    return generator.add_constant(BigInt::create(generator.vm(), move(integer)), Bytecode::Generator::DeduplicateConstant::No);
 }
 
 Bytecode::CodeGenerationErrorOr<Optional<Bytecode::Operand>> StringLiteral::generate_bytecode(Bytecode::Generator& generator, [[maybe_unused]] Optional<Bytecode::Operand> preferred_dst) const

Userland/Libraries/LibJS/Bytecode/Instruction.h

@@ -82,7 +82,6 @@
     O(Mov)                             \
     O(Mul)                             \
     O(NewArray)                        \
-    O(NewBigInt)                       \
     O(NewClass)                        \
     O(NewFunction)                     \
     O(NewObject)                       \

Userland/Libraries/LibJS/Bytecode/Interpreter.cpp

@@ -63,6 +63,8 @@ static ByteString format_operand(StringView name, Operand operand, Bytecode::Exe
             builder.appendff("Int32({})", value.as_i32());
         else if (value.is_double())
             builder.appendff("Double({})", value.as_double());
+        else if (value.is_bigint())
+            builder.appendff("BigInt({})", value.as_bigint().to_byte_string());
         else if (value.is_string())
             builder.appendff("String(\"{}\")", value.as_string().utf8_string_view());
         else if (value.is_undefined())
@@ -854,13 +856,6 @@ static ThrowCompletionOr<Value> typeof_(VM& vm, Value value)
 
 JS_ENUMERATE_COMMON_UNARY_OPS(JS_DEFINE_COMMON_UNARY_OP)
 
-ThrowCompletionOr<void> NewBigInt::execute_impl(Bytecode::Interpreter& interpreter) const
-{
-    auto& vm = interpreter.vm();
-    interpreter.set(dst(), BigInt::create(vm, m_bigint));
-    return {};
-}
-
 ThrowCompletionOr<void> NewArray::execute_impl(Bytecode::Interpreter& interpreter) const
 {
     auto array = MUST(Array::create(interpreter.realm(), 0));
@@ -1613,13 +1608,6 @@ ByteString Mov::to_byte_string_impl(Bytecode::Executable const& executable) cons
         format_operand("src"sv, m_src, executable));
 }
 
-ByteString NewBigInt::to_byte_string_impl(Bytecode::Executable const& executable) const
-{
-    return ByteString::formatted("NewBigInt {}, {}",
-        format_operand("dst"sv, dst(), executable),
-        m_bigint.to_base_deprecated(10));
-}
-
 ByteString NewArray::to_byte_string_impl(Bytecode::Executable const& executable) const
 {
     StringBuilder builder;

Userland/Libraries/LibJS/Bytecode/Op.h

@@ -239,26 +239,6 @@ private:
     Operand m_excluded_names[];
 };
 
-class NewBigInt final : public Instruction {
-public:
-    NewBigInt(Operand dst, Crypto::SignedBigInteger bigint)
-        : Instruction(Type::NewBigInt, sizeof(*this))
-        , m_dst(dst)
-        , m_bigint(move(bigint))
-    {
-    }
-
-    ThrowCompletionOr<void> execute_impl(Bytecode::Interpreter&) const;
-    ByteString to_byte_string_impl(Bytecode::Executable const&) const;
-
-    Operand dst() const { return m_dst; }
-    Crypto::SignedBigInteger const& bigint() const { return m_bigint; }
-
-private:
-    Operand m_dst;
-    Crypto::SignedBigInteger m_bigint;
-};
-
 // NOTE: This instruction is variable-width depending on the number of elements!
 class NewArray final : public Instruction {
 public: