[flang] Linker error when calling ieee_set_halting_mode from a subroutine

Dear all,
when I compile this minimal example
```fortran
use, intrinsic :: ieee_exceptions
call foo ( .false. )
contains
subroutine foo ( ieee_halting )
logical, intent(in) :: ieee_halting
if ( ieee_support_halting(ieee_overflow) ) &
call ieee_set_halting_mode ( ieee_overflow, halting = ieee_halting )
end subroutine foo
end
```
I get this error :
```
flang truc.f90
Undefined symbols for architecture arm64:
"_fedisableexcept", referenced from:
__QFPfoo in truc-917008.o
"_feenableexcept", referenced from:
__QFPfoo in truc-917008.o
"_fegetexcept", referenced from:
__QFPfoo in truc-917008.o
ld: symbol(s) not found for architecture arm64
flang-21: error: linker command failed with exit code 1 (use -v to see invocation)
```
```
flang --version
Homebrew flang version 21.1.8
Target: arm64-apple-darwin24.6.0
Thread model: posix
InstalledDir: /opt/homebrew/Cellar/flang/21.1.8/libexec
Configuration file: /opt/homebrew/Cellar/flang/21.1.8/libexec/flang.cfg
Configuration file: /opt/homebrew/etc/clang/arm64-apple-darwin24.cfg
```

The issue goes away if ieee_set_halting_mode is called directly from the main program :
```
use, intrinsic :: ieee_exceptions
logical :: ieee_halting = .false.
if ( ieee_support_halting(ieee_overflow) ) &
call ieee_set_halting_mode ( ieee_overflow, halting = ieee_halting )
end
```

Start with the minimal Fortran example and the flang --version details in the issue, reproducing it on arm64-apple-darwin24.6.0. Investigate how ieee_set_halting_mode is linked when called from a subroutine versus the main program; done means the example links and runs without the undefined fedisableexcept, feenableexcept, and fegetexcept symbols.

Written by the indexing model from the issue text.