Vector subscript out of range on decompiling shader.

[smb123w64gb]

Was trying to decompile sm4sh shader and it hit a "vector subscript out of range" error.
Ill include a sample to reproduce the error.

CustumShader.zip

[neobrain]

This is probably due to the issue addressed in https://github.com/citra-emu/citra/pull/1479.

MAD instruction use a slightly different encoding than originally thought. nihstro's disassembler/assembler haven't been adapted to consider this properly, yet.