[clang] [analyzer][NFC] Simplifications in ArrayBoundV2 (PR #67572)

[via cfe-commits]

DonatNagyE wrote:

After some delays (I had a short vacation, then forgot about this patch) I finally got some test results... and they revealed that it was causing lots of segfaults. @steakhal thanks for asking for the experimental confirmation, it was useful!

After fixing the buggy line and pushing the update, I re-analyzed the open source projects, and this produced the intended results: the analysis did not crash and the set of the reports did not change. Based on this I think that this commit is ready to be merged now.

For reference, I insert the table of the test results, but it contains no differences:
| CodeChecker results | | |
| --- | --- | --- |
| bitcoin_v0.20.1_baseline_vs_bitcoin_v0.20.1_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=bitcoin_v0.20.1_baseline&newcheck=bitcoin_v0.20.1_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=bitcoin_v0.20.1_baseline&newcheck=bitcoin_v0.20.1_new&is-unique=on&diff-mode=Resolved) |
| redis_6.2.6_baseline_vs_redis_6.2.6_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=redis_6.2.6_baseline&newcheck=redis_6.2.6_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=redis_6.2.6_baseline&newcheck=redis_6.2.6_new&is-unique=on&diff-mode=Resolved) |
| protobuf_v3.13.0_baseline_vs_protobuf_v3.13.0_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=protobuf_v3.13.0_baseline&newcheck=protobuf_v3.13.0_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=protobuf_v3.13.0_baseline&newcheck=protobuf_v3.13.0_new&is-unique=on&diff-mode=Resolved) |
| ffmpeg_n4.3.1_baseline_vs_ffmpeg_n4.3.1_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=ffmpeg_n4.3.1_baseline&newcheck=ffmpeg_n4.3.1_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=ffmpeg_n4.3.1_baseline&newcheck=ffmpeg_n4.3.1_new&is-unique=on&diff-mode=Resolved) |
| postgres_REL_13_0_baseline_vs_postgres_REL_13_0_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=postgres_REL_13_0_baseline&newcheck=postgres_REL_13_0_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=postgres_REL_13_0_baseline&newcheck=postgres_REL_13_0_new&is-unique=on&diff-mode=Resolved) |
| sqlite_version-3.33.0_baseline_vs_sqlite_version-3.33.0_new | [New reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=sqlite_version-3.33.0_baseline&newcheck=sqlite_version-3.33.0_new&is-unique=on&diff-mode=New) | [Lost reports](https://codechecker-demo.eastus.cloudapp.azure.com/Default/reports?run=sqlite_version-3.33.0_baseline&newcheck=sqlite_version-3.33.0_new&is-unique=on&diff-mode=Resolved) |

https://github.com/llvm/llvm-project/pull/67572