[ILVerify] Reporting verification error on protected blocks with more than one handler

[TIHan]

Adds an additional check in ILVerify as described here: #63198 (comment)

Description

ECMA-335 states:

I.12.4.2 Exception handling
There are four kinds of handlers for protected blocks. A single protected block shall have exactly
one handler associated with it:

• A finally handler that shall be executed whenever the block exits, regardless of
  whether that occurs by normal control flow or by an unhandled exception.
• A fault handler that shall be executed if an exception occurs, but not on completion of
  normal control flow.
• A catch handler that handles any exception of a specified class or any of its sub-classes.
• A filter handler that runs a user-specified set of CIL instructions to determine if the
  exception should be handled by the associated handler, or passed on to the next
  protected block.

Currently, ILVerify does not check for A single protected block shall have exactly one handler associated with it, and the assembly would pass verification if a try block had more than one handler.

Acceptance Criteria

• Add tests

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Issue Details

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Adds an additional check in ILVerify as described here: #63198 (comment)

Description

ECMA-335 states:

I.12.4.2 Exception handling
There are four kinds of handlers for protected blocks. A single protected block shall have exactly
one handler associated with it:

• A finally handler that shall be executed whenever the block exits, regardless of
  whether that occurs by normal control flow or by an unhandled exception.
• A fault handler that shall be executed if an exception occurs, but not on completion of
  normal control flow.
• A catch handler that handles any exception of a specified class or any of its sub-classes.
• A filter handler that runs a user-specified set of CIL instructions to determine if the
  exception should be handled by the associated handler, or passed on to the next
  protected block.

Currently, ILVerify does not check for A single protected block shall have exactly one handler associated with it, and the assembly would pass verification if a try block had more than one handler.

Acceptance Criteria

• Add tests

Author:	TIHan
Assignees:	TIHan
Labels:	area-crossgen2-coreclr, area-ILVerification
Milestone:	-

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Draft Pull Request was automatically closed for inactivity. Please let us know if you'd like to reopen it.

[JulieLeeMSFT]

@TIHan you moved this to .NET 8. Please make this as a draft PR.