[CONTRACTS] DFCC loop assigns infererence with functions inlined

[qinheping]

Current loop assigns inference of DFCC can only infer targets considering only instructions in the same function. However, variables may be written to in the call of another function from function call inside the loop. So in this PR, we infer loop assigns based on a copy of the function and inlining all calls in the copy.

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[codecov]

Codecov Report

Attention: Patch coverage is 84.69388% with 15 lines in your changes missing coverage. Please review.

Project coverage is 78.80%. Comparing base (018c61c) to head (0444fad).

Files with missing lines	Patch %	Lines
...ntracts/dynamic-frames/dfcc_infer_loop_assigns.cpp	84.70%	13 Missing ⚠️
...trument/contracts/dynamic-frames/dfcc_cfg_info.cpp	84.61%	2 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## develop #8490 +/- ##
===========================================
- Coverage 78.90% 78.80% -0.11% 
===========================================
Files 1727 1727 Lines 198425 198785 +360 Branches 18523 18529 +6 ===========================================
+ Hits 156561 156643 +82 - Misses 41864 42142 +278 

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[qinheping]

We also switch to a more aggressive loop-assigns widening strategy that also widens all dereference to whole object. The reason to do so is that it fits better for Kani loop contracts, while we have a good loop assigns specification support for C loop contracts for which the inference is less needed.

[tautschnig]

Is this change now strictly necessary given the additional widening?

[qinheping]

Yes, new addition widening will infer object_whole(data), i which is not accurate for this test.