[Clang] [CodeGen] Fix codegen bug in constant initialisation in C23 mode (#84981)

Consider the following code:
```c
bool const inf =  (1.0/0.0);
``` 

When trying to emit the initialiser of this variable in C23, we end up
hitting a code path in codegen in `VarDecl::evaluateValueImpl()` where
we check for `IsConstantInitialization && (Ctx.getLangOpts().CPlusPlus
|| Ctx.getLangOpts().C23)`, and if that is the case and we emitted any
notes, constant evaluation fails, and as a result, codegen issues this
error:
```
<source>:1:12: error: cannot compile this static initializer yet
    1 | bool const inf =  (1.0/0.0);
      |        
```

As a fix, only fail in C23 mode if we’re initialising a `constexpr`
variable.

This fixes #84784.

0 files changed, 0 insertions, 0 deletions