Warn when ana.opt.hashcons is disabled but implicitly overridden, fail for Apron

[Copilot]

Plan: Warn when ana.opt.hashcons is off but hashconsing is forced on

• Understand the issue: ana.opt.hashcons=false is overridden when exp.arg.enabled, witness.graphml.enabled, or Apron domain is on
• Add warning logic in the general config compatibility check location
• Remove tests (not needed per reviewer feedback)
• Remove accidentally committed _codeql_detected_source_root file
• Address reviewer feedback to make Apron check a fail instead of warn
• Add usesApron flag to MCPRegistry for proper Apron detection
• Swap order of checks (Apron fail before ARG warn)
• Run code review and security checks

Changes made:

Added warnings/failures in check_arguments() in maingoblint.ml:

• Failure when ana.opt.hashcons is disabled but Apron domains are activated (checked first - Apron requires hashconsing for compare operation and will crash without it)
• Warning when ana.opt.hashcons is disabled but exp.arg.enabled is on (checked second - covers witness generation use case)
• Checks placed alongside other config compatibility checks

Added usesApron flag to MCPRegistry:

• Added optional ~usesApron parameter (default false) to MCPRegistry.register_analysis()
• Added any_activated_uses_apron() function to check if any activated analysis uses Apron
• Marked all Apron analyses (apronAnalysis, affineEqualityAnalysis, linearTwoVarEqualityAnalysis) with ~usesApron:true flag
• This provides proper registry-based detection instead of string matching on analysis names

Kept variable refactoring in control.ml for consistency:

• hashcons_enabled variable used throughout spec construction

Removed test files per @michael-schwarz's feedback that tests are not needed

Removed _codeql_detected_source_root file that was accidentally committed

The changes properly fail for the Apron case (which would crash) and warn for the ARG/witness case where hashconsing is implicitly enabled.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Warn when ana.opt.hashcons is off, but witness.graphml.enabled or exp.arg.enabled are on or an Apron domain is on</issue_title>
<issue_description>In theses cases, counterintuitively, --disable ana.opt.hashcons doesn't completely disable hashconsing, as observed by @sim642

analyzer/src/framework/control.ml

Line 19 in f214ec5

let arg_enabled = get_bool "witness.graphml.enabled" || get_bool "exp.arg.enabled" in

analyzer/src/framework/control.ml

Lines 29 to 31 in f214ec5

	(* hashcons before witness to reduce duplicates, because witness re-uses contexts in domain and requires tag for PathSensitive3 *)
	|> lift (get_bool "ana.opt.hashcons" || arg_enabled) (module HashconsContextLifter)
	|> lift arg_enabled (module HashconsLifter)

</issue_description>

Comments on the Issue (you are @copilot in this section)

@sim642 As to the Apron domain use case (getting a totally-ordered `compare` for a type with just `equal` and `hash`), a thing to explore could also be wrapping hashconsing directly around that domain, instead of relying on some very outermost hashconsing to implement `compare` such that Goblint wouldn't crash outright.

• Fixes Warn when ana.opt.hashcons is off, but witness.graphml.enabled or exp.arg.enabled are on or an Apron domain is on #1657

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[michael-schwarz]

@copilot this should be move to the general place where we check whether configs are compatible.

[michael-schwarz]

@copilot tests for this issue are not needed.

[Copilot]

@copilot this should be move to the general place where we check whether configs are compatible.

Done! Moved the warnings to check_arguments() in maingoblint.ml where other config compatibility checks are performed. See commit 88c9ac6.

[Copilot]

@copilot tests for this issue are not needed.

Removed the test files. See commit daa36fb.