[compiler-rt] [compiler-rt][builtins]Fix complex division for aarch64 (PR #106664)

[Alexander Shaposhnikov via llvm-commits]

alexander-shaposhnikov wrote:

Thanks for looking into this.
Let me quote https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf 
p.467 
```
G.3 Conventions
1 A complex or imaginary value with at least one infinite part is regarded as an infinity
(even if its other part is a NaN). A complex or imaginary value is a finite number if each
of its parts is a finite number (neither infinite nor NaN). A complex or imaginary value is
a zero if each of its parts is a zero.
```
p. 469 
```
— if the first operand is a finite number and the second operand is an infinity, then the
result of the / operator is a zero;
```
I'm wondering if I'm misinterpreting it, please feel free to correct me.

Regarding -ffp-model=strict - need to check.

https://github.com/llvm/llvm-project/pull/106664