[llvm] [symbolizer] Address starting with a plus sign is valid. (PR #135857)

[Serge Pavlov via llvm-commits]

spavloff wrote:

This change does not add any new capabilities; it is purely syntactic sugar. Syntactic sugar is OK when it provides additional convenience, such as shorter commands or improved readability. Typically, there is no intention to merely expand the set of allowed constructs without clear benefits.

Addresses, by their nature, are unsigned. Using a plus sign in address specifications does not seem useful. Supporting unnecessary syntax may even introduce errors. For example, if a script invokes `llvm-symbolizer` with arguments like `$BASE+1234`, and the script doesn't define $BASE due to an error, the address would resolve to +1234. In the original implementation, this would raise an error, but with this change, it could output garbage instead.

Before adopting this patch, we need understand how this change could be useful.

https://github.com/llvm/llvm-project/pull/135857