[ignition] Expect 'I' for signed bytecode operands

test/cctest/interpreter/bytecode_expectations/Throw.golden

 #
 # Autogenerated by generate-bytecode-expectations.
 #
 
 ---
 wrap: yes
 
 ---
 snippet: "
   throw 1;
 "
 frame size: 0
 parameter count: 1
 bytecode array length: 4
 bytecodes: [
   /*   30 E> */ B(StackCheck),
-  /*   34 S> */ B(LdaSmi), U8(1),
+  /*   34 S> */ B(LdaSmi), I8(1),
   /*   34 E> */ B(Throw),
 ]
 constant pool: [
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   throw 'Error';
@@ skipping 14 matching lines @@
 
 ---
 snippet: "
   var a = 1; if (a) { throw 'Error'; };
 "
 frame size: 1
 parameter count: 1
 bytecode array length: 12
 bytecodes: [
   /*   30 E> */ B(StackCheck),
-  /*   42 S> */ B(LdaSmi), U8(1),
+  /*   42 S> */ B(LdaSmi), I8(1),
                 B(Star), R(0),
   /*   45 S> */ B(JumpIfToBooleanFalse), U8(5),
   /*   54 S> */ B(LdaConstant), U8(0),
   /*   54 E> */ B(Throw),
                 B(LdaUndefined),
   /*   72 S> */ B(Return),
 ]
 constant pool: [
   ONE_BYTE_INTERNALIZED_STRING_TYPE ["Error"],
 ]
 handlers: [
 ]