Should detect/model double parameter as such

Decompile https://github.com/rfalke/decompiler-subjects/blob/master/from_holdec/i386_call_type_promotion/ia32_elf/subject.exe

Output:
```
int32_t print_double_as_hex(float80_t a1, uint32_t a2) {
```

while it should be
```
int32_t print_double_as_hex(float64_t a1) {
```

Start by reproducing the decompilation of subject.exe from the linked decompiler-subjects case and compare the actual signature with the expected one. Trace the handling of the double parameter and the extra uint32_t parameter through the relevant decompilation output; done means the function is emitted as print_double_as_hex(float64_t a1) without the spurious second parameter.

Written by the indexing model from the issue text.