Fix naming-convention false positive on Yul-local function parameters

[MarkLee131]

Fixes #3037. Also addresses #1815 (open since 2023).

naming-convention was flagging parameters of functions defined inside inline assembly with their parser-mangled internal name, e.g. Parameter LibArr.unsafeExtend.asm_0.extendInline().base__unsafeExtend_asm_0_extendInline is not in mixedCase for a source-level base_.

Root Cause

The Yul parser mangles every local identifier to <source_name>__<scope_chain> (solc_parsing/yul/parse_yul.py:130), so a Yul parameter base_ declared inside unsafeExtend's 0th assembly block ends up named base__unsafeExtend_asm_0_extendInline. The detector iterates contract.functions_declared, which includes synthetic Yul-local functions, and then runs is_mixed_case_with_underscore on the mangled name.

The mangled name is a parser artifact, not an identifier the developer wrote. Slither already tracks this distinction: synthetic Yul functions carry Function.internal_scope non-empty (set when the parser binds them under their containing YulBlock).

Fix

Skip Yul-local functions in the naming-convention loop:

for func in contract.functions_declared:
    if func.is_constructor:
        continue
    if func.internal_scope:
        # Synthetic function defined inside inline assembly. Its name and
        # parameter names are parser-mangled artifacts, not source identifiers.
        continue
    ...

Tests

Added tests/e2e/detectors/test_data/naming-convention/0.8.20/naming_convention_yul_local.sol. Covers two Yul-local function declarations (extendInline, memcpy) plus a tripwire tripwire(uint256 Bad_Param) that uses a deliberately non-mixedCase Solidity-level parameter. After the fix the snapshot contains exactly the tripwire finding; the Yul-local FPs are gone.

All 8 existing NamingConvention fixtures (0.4.25 / 0.5.16 / 0.6.11 / 0.7.6 × naming_convention.sol and no_warning_for_public_constants.sol) still pass with identical output.

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