ci: add -fno-builtin to bindgen builder

[Copilot]

Fixes a build failure caused by a newly introduced rustc lint suspicious_runtime_symbol_definitions.

The lint fails because bindgen maps size_t to c_ulonglong/u64 instead of usize for functions like memcpy, strlen etc. The reason bindgen behaves like this is because clang silently replaces any declarations of such functions in the input C code with its own builtins with the same names. Since the builtins use unsigned long long instead of size_t bindgen emits c_ulonglong instead of usize.

The fix is to pass -fno-builtin to clang which ensures it does not replace aforesaid functions with builtins.

[Copilot]

Pull request overview

This PR updates wdk-build’s bindgen configuration to avoid Clang substituting certain standard-library function declarations (e.g., memcpy, strlen) with builtin signatures, which can cause bindgen to emit Rust bindings with u64/c_ulonglong sizes and trip the new rustc lint suspicious_runtime_symbol_definitions.

Changes:

• Add -fno-builtin to the bindgen Clang invocation so function signatures retain size_t (and therefore bindgen’s expected Rust mapping).
• Document the rationale for the flag directly in the builder configuration.

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.78%. Comparing base (0e3499d) to head (4b24ab8).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #695   +/-   ##
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  Coverage   79.78%   79.78%           
=======================================
  Files          26       26           
  Lines        5590     5590           
  Branches     5590     5590           
=======================================
  Hits         4460     4460           
  Misses       1001     1001           
  Partials      129      129           

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