Add AddressSanitizer support for clang-cl builds

Select the clang-cl-asan CMake preset (RelWithDebInfo, clang-cl,
ADDRESS_SANITIZER=ON) to instrument first-party code with AddressSanitizer.
The wiring lives in cmake/AddressSanitizer.cmake; SANITIZERS.md tells how to
add the clang-cl tools, build, and read the report.

Details:
- Add the clang-cl-asan preset so the asan build is one selection in Visual
  Studio, and a base for a CMakeUserPresets.json to inherit.
- Instrument first-party code only; the vendored libraries keep default flags.
- Use the release CRT and disable MSVC-STL container annotations, so
  instrumented and un-instrumented TUs stay compatible.
- Pass /bigobj to the TUs asan inflates past the COFF section cap.
- Link the asan runtime for clang-cl (lld-link does not infer it).
- Stub Bink into the exe: retail binkw32.dll cannot load in an asan process
  (its image base is the 32-bit shadow), so compile no-op exports instead.
- Route the asan report to gamedir/asan.report.<pid>, since every app is a
  WIN32 GUI app with no console to receive the default stderr report.
- Opt functions with 32-bit inline __asm out of instrumentation with
  cmake/asan-ignorelist.txt, one function at a time (asan reserves a register
  the asm needs). The rest of each translation unit stays instrumented.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -9,3 +9,6 @@
 /CMakeUserPresets.json
 /CMakeSettings.json
 /lib/
+
+# AddressSanitizer reports (see SANITIZERS.md)
+/gamedir/asan.report.*