Use of partially written variable during optimized divide fails to simplify

[D0ntPanic]

If intermediate stages of an optimized divide use partial variable writes, the expression fails
to simplify into a division expression.

Binaries with examples:

partial_write.zip

u8_div_4k_x64.so: See 3, 5, 6, 7, 9, and others
u16_div_4k_x64.so: See 7, 21, 23, 25, and others
i16_div_4k_x64.so: See 3, 5, 6, 7, 9, and others
i8_div_4k_x86.so: See 3, 5, 6, 7, 9, and others
i16_div_4k_x86.so: See 3, 5, 6, 7, 9, and others
u8_div_4k_x86.so: See 3, 5, 6, 7, 9, and others
u16_div_4k_x86.so: See 7, 21, 23, 25, and others