When dumping icode, include string constants

[andreabergia]

When Token.printICode is set to true (generally only for debugging purposes), Rhino prints all the interpreter bytecode it generated. For the Icode_REG_STRxx instructions Rhino will also print inline the string value, but it does not do it for the (far more common) Icode_REG_STR_Cxx instructions.

This tiny PR just extends the same behavior to the Icode_REG_STR_Cxx. Therfore, for this js code:

a + b

it will now print this:

ICode dump, for null, length = 10
MaxStack = 2
 [0] LINE : 2
 [3] REG_STR_C0 "a"
 [4] NAME
 [5] REG_STR_C1 "b"
 [6] NAME
 [7] ADD
 [8] POP_RESULT
 [9] RETURN_RESULT

whereas the old version would have just printed something like:

 [3] REG_STR_C0

There are no unit tests for all this stuff, but it's currently being used only for debugging purposes... so I didn't really think that it was worth creating a whole test suite from scratch for this change.

[rbri]

@andreabergia build fails because of spotless...

[andreabergia]

@andreabergia build fails because of spotless...

🤦 I'll learn... eventually

[gbrail]

Seems very reasonable to me. Thanks!