i#7487: fix tool's crashes due to cfg thunk implemented on 24h2 and above

[x9090]

This commit fixes the crashes on the tool when it encounters cfg thunks guard_dispatch_icall$thunk$xxx that was dereferenced to extended image memory located at ntdll by OS kernel, which leads to invalid memory for private library.

Apart from that, redirect_GetModuleFileNameW seems to be broken as it returns the ascii version for the filename instead of unicode version.

Fixes #7487

[x9090]

Apparently, the fix in redirect_GetModuleFileNameW has uncovered the broken drsyms module, which was revealed when I called the drsym_lookup_symbol. I will create a separate issues to explain the broken drsyms module on Windows which is somewhat related to the currently unsupported delay-loaded DLL that contains TLS.

From the CI's logs, it turns out that the tools/applications attempt to call drsyms module will lead to the loading of symsrv.dll which is currently not found in the build directory.

2025-11-13T03:13:48.6140630Z 204: Test command: D:\a\dynamorio\dynamorio\build_debug-internal-64\bin64\drrun.exe "-s" "90" "-quiet" "-debug" "-use_dll" "D:/a/dynamorio/dynamorio/build_debug-internal-64/lib64/debug/dynamorio.dll" "-exit0" "-stderr_mask" "0xC" "-msgbox_mask" "0" "-dumpcore_mask" "0x7d" "-staged" "-code_api" "-c" "D:/a/dynamorio/dynamorio/build_debug-internal-64/api/samples/../bin/instrcalls.dll" "--" "D:/a/dynamorio/dynamorio/build_debug-internal-64/suite/tests/bin/common.eflags.exe"
2025-11-13T03:13:48.6926549Z 204: Working Directory: D:/a/dynamorio/dynamorio/build_debug-internal-64/suite/tests
2025-11-13T03:13:48.7241676Z 204: Test timeout computed to be: 120
2025-11-13T03:13:48.8021294Z 204: <Application D:\a\dynamorio\dynamorio\build_debug-internal-64\suite\tests\bin\common.eflags.exe (2096). Unable to load client library: D:\a\dynamorio\dynamorio\build_debug-internal-64\api\bin/symsrv.dll
2025-11-13T03:13:48.8957432Z 204: 	Cannot find library.>

[ivankyluk]

Thank you for contributing. Please request a review when all the tests have passed.