Fix RULE-5-10-1 false positives on compiler-predefined function identifiers

[castler]

Description

RULE-5-10-1 (poorly-formed identifier) flagged the compiler-predefined
function identifiers func, FUNCTION and PRETTY_FUNCTION for
containing double underscores / leading underscores. These are not
user-defined identifiers: func is mandated by the C++ standard and
FUNCTION/PRETTY_FUNCTION are GCC/Clang extensions, synthesized
once per enclosing function. They frequently surface via assert-style
macros, producing one finding per macro invocation site (on this
codebase, 228 findings, ~79% of the rule's results).

The shared IdentifierIntroduction library already excludes
variable.isCompilerGenerated(), but the extractor does not mark these
predefined variables as compiler generated, so they leak through.

Exclude them in VariableDeclarationEntryIdentifier using a
name-independent structural signal: they are static local variables
with no definition (their only declaration entry is located at a use
site), whereas a genuine static local always has an in-source
definition. This deliberately avoids hard-coding the names, so a user
who really declares such an identifier (on a compiler that does not
predefine it) still has a definition and is therefore still flagged.

Fixes #1170

Change request type

• Release or process automation (GitHub workflows, internal scripts)
• Internal documentation
• External documentation
• Query files (.ql, .qll, .qls or unit tests)
• External scripts (analysis report or other code shipped as part of a release)

Rules with added or modified queries

• No rules added
• Queries have been added for the following rules:
  • rule number here
• Queries have been modified for the following rules:
  • RULE-5-10-1

Release change checklist

A change note (development_handbook.md#change-notes) is required for any pull request which modifies:

• The structure or layout of the release artifacts.
• The evaluation performance (memory, execution time) of an existing query.
• The results of an existing query in any circumstance.

If you are only adding new rule queries, a change note is not required.

Author: Is a change note required?

• Yes
• No

🚨🚨🚨
Reviewer: Confirm that format of shared queries (not the .qll file, the
.ql file that imports it) is valid by running them within VS Code.

• Confirmed

Reviewer: Confirm that either a change note is not required or the change note is required and has been added.

• Confirmed

Query development review checklist

For PRs that add new queries or modify existing queries, the following checklist should be completed by both the author and reviewer:

Author

• Have all the relevant rule package description files been checked in?
• Have you verified that the metadata properties of each new query is set appropriately?
• Do all the unit tests contain both "COMPLIANT" and "NON_COMPLIANT" cases?
• Are the alert messages properly formatted and consistent with the style guide?
• Have you run the queries on OpenPilot and verified that the performance and results are acceptable?
  As a rule of thumb, predicates specific to the query should take no more than 1 minute, and for simple queries be under 10 seconds. If this is not the case, this should be highlighted and agreed in the code review process.
• Does the query have an appropriate level of in-query comments/documentation?
• Have you considered/identified possible edge cases?
• Does the query not reinvent features in the standard library?
• Can the query be simplified further (not golfed!)

Reviewer

• Have all the relevant rule package description files been checked in?
• Have you verified that the metadata properties of each new query is set appropriately?
• Do all the unit tests contain both "COMPLIANT" and "NON_COMPLIANT" cases?
• Are the alert messages properly formatted and consistent with the style guide?
• Have you run the queries on OpenPilot and verified that the performance and results are acceptable?
  As a rule of thumb, predicates specific to the query should take no more than 1 minute, and for simple queries be under 10 seconds. If this is not the case, this should be highlighted and agreed in the code review process.
• Does the query have an appropriate level of in-query comments/documentation?
• Have you considered/identified possible edge cases?
• Does the query not reinvent features in the standard library?
• Can the query be simplified further (not golfed!)