Fix Bugzilla 24848 - bad parser diagnostic for a partial MulExp

[ntrel]

No description provided.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	24848	minor	bad parser diagnostic for a partial MulExp

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#17055"

[ntrel]

I don't know why some tests for fail_compilation/traits_alone.d are passing but some failing:

-fail_compilation/traits_alone.d(11): Error: no identifier for declarator `__error`
+fail_compilation/traits_alone.d(11): Error: no identifier for declarator `_error_`

[ntrel]

OK, seems to be just an unrelated error now:

./generated/windows/release/64/loadlibwin.exe 
D:\a\1\s\druntime\test\shared\src\linkDR.c : fatal error C1083: Cannot open compiler generated file: 'D:\a\1\s\druntime\test\shared\generated\windows\release\64.obj': Permission denied
make[2]: *** [../common.mak:113: generated/windows/release/64/linkDR.exe] Error 1