LibJS: Support non-base-10 BigInt literals in bytecode VM

Fixes 39 tests in test262 and a handful in test-js. :^)

Userland/Libraries/LibJS/Bytecode/ASTCodegen.cpp

@@ -498,7 +498,19 @@ Bytecode::CodeGenerationErrorOr<void> NullLiteral::generate_bytecode(Bytecode::G
 
 Bytecode::CodeGenerationErrorOr<void> BigIntLiteral::generate_bytecode(Bytecode::Generator& generator) const
 {
- generator.emit<Bytecode::Op::NewBigInt>(Crypto::SignedBigInteger::from_base(10, m_value.substring(0, m_value.length() - 1)));
+ // 1. Return the NumericValue of NumericLiteral as defined in 12.8.3.
+ auto integer = [&] {
+ if (m_value[0] == '0' && m_value.length() >= 3)
+ if (m_value[1] == 'x' || m_value[1] == 'X')
+ return Crypto::SignedBigInteger::from_base(16, m_value.substring(2, m_value.length() - 3));
+ if (m_value[1] == 'o' || m_value[1] == 'O')
+ return Crypto::SignedBigInteger::from_base(8, m_value.substring(2, m_value.length() - 3));
+ if (m_value[1] == 'b' || m_value[1] == 'B')
+ return Crypto::SignedBigInteger::from_base(2, m_value.substring(2, m_value.length() - 3));
+ return Crypto::SignedBigInteger::from_base(10, m_value.substring(0, m_value.length() - 1));
+ }();
+
+ generator.emit<Bytecode::Op::NewBigInt>(integer);
  return {};
 }