Improve support for post-increment/decrement on pointers

[ElektroKill]

Link to issue(s) this covers:
#2620 (This PR only partially resolves this issue)

Problem

ILSpy did not properly handle post-increment and post-decrement on pointers for other pointer types than byte*

Solution

• Extend pattern-matching logic to support more post-increment and post-decrement cases
• Re-enabled a previously disabled test in CompoundAssignmentTest pretty test which tests this newly added behavior.