support set_name of InstructionValue, IntValue, etc

[taquangtrung]

Hi,

Description

In this PR, I expose the set_name function to several LLVM Values, like InstructionValule, IntValue, etc.

This feature is important when inkwell is used to optimize or transform LLVM bitcode, the users can call set_name to rename the optimized/transformed instructions, variables, etc.

Related Issue

It's a new feature, so I didn't create any issues. Instead, we can discuss the details here if necessary.

How This Has Been Tested

My implementation is just a wrapper to the function set_name in Value data structure, which is already well tested. So, I didn't write any new unit tests.

Option<Breaking Changes>

No breaking change.

Checklist

• [x] I have read the Contributing Guide