Write a RISC-style subroutine called ALLCAPS that accepts a parameter in a 32-bit register representing the starting address STRNG in the main memory for a string of ASCII characters in successive bytes, with the NUL control character (value 0) at the end of the string. The subroutine should scan the string beginning at address STRNG and replace every occurrence of a lower-case letter ('a'?'z') with the corresponding upper-case letter ('A'?'Z').