[llvm] [LLVM][Support] check for error return from dladdr. (PR #138369)

[via llvm-commits]

jeremyd2019 wrote:

As promised to @mstorsjo in https://github.com/llvm/llvm-project/pull/138117#issuecomment-2846028231.

> On success, these functions return a nonzero value.

https://github.com/llvm/llvm-project/pull/138369