Multiplication by one is also trivial. Depending on the registers
involved, either a single MOV or no instructions will be generated.
Before:
0x52800038 mov w24, #0x1
0x1b1a7f1b mul w27, w24, w26
After:
0x2a1a03fb mov w27, w26
Before:
0x52800039 mov w25, #0x1
0x1b1a7f3a mul w26, w25, w26
After:
Nothing!
f25611f388