[flang-commits] [clang] [flang] Revert "Revert "[Flang][Driver] Add a flag to control zero initializa… (PR #123097)

[Kiran Chandramohan via flang-commits]

kiranchandramohan wrote:

Apologies for the churn here. But the previous patch (https://github.com/llvm/llvm-project/pull/122144) was causing some non-deterministic failures in `flang/test/Lower/module_use.f90`. I am assuming this is because the LoweringOpt is not set to a reasonable value in the bbc flow. (there is a default, not clear why it is not being set in the bbc flow). I am fixing this by adding a similar flag to bbc.

Another reason I thought was the following.
```
The test that fails is flang/test/Lower/module_use.f90. This test also compiles another test flang/test/Lower/module_definition.f90. Is there an issue with compiling the same test with modules two times and can they interact badly? This used to be the case in Classic Flang.
```

https://github.com/llvm/llvm-project/pull/123097