Fix build break with clang-21 on linux-x64

[HJLeee]

linux-x64 build with clang-21 fails with below error.

[  248s] In file included from /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/SOS/Strike/disasm.cpp:57:
[  248s] In file included from /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/gcdump/gcdumpnonx86.cpp:13:
[  248s] In file included from /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/inc/gcinfodecoder.h:170:
[  248s] /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/inc/regdisp.h:261:16: error: first argument in call to 'memset' is a pointer to non-trivially copyable type 'REGDISPLAY' [-Werror,-Wnontrivial-memcall]
[  248s]   261 |         memset(this, 0, sizeof(REGDISPLAY));
[  248s]       |                ^
[  248s] /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/inc/regdisp.h:261:16: note: explicitly cast the pointer to silence this warning
[  248s]   261 |         memset(this, 0, sizeof(REGDISPLAY));
[  248s]       |                ^
[  248s]       |                (void*)
[  248s] In file included from /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/SOS/Strike/disasm.cpp:57:
[  248s] In file included from /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/gcdump/gcdumpnonx86.cpp:591:
[  248s] /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/gcdump/../gcinfo/gcinfodumper.cpp:620:16: error: first argument in call to 'memset' is a pointer to non-trivially copyable type 'REGDISPLAY' [-Werror,-Wnontrivial-memcall]
[  248s]   620 |     ZeroMemory(&regdisp, sizeof(regdisp));
[  248s]       |                ^
[  248s] /home/abuild/rpmbuild/BUILD/coreclr-diagnostics-8.0.547301/src/shared/gcdump/../gcinfo/gcinfodumper.cpp:620:16: note: explicitly cast the pointer to silence this warning
[  248s] 2 errors generated.
[  248s] make[2]: *** [src/SOS/Strike/CMakeFiles/sos.dir/build.make:79: src/SOS/Strike/CMakeFiles/sos.dir/disasm.cpp.o] Error 1
[  248s] make[2]: *** Waiting for unfinished jobs....
[  248s] [ 99%] Linking CXX shared library libdbgshim.so
[  248s] [ 99%] Built target dbgshim
[  249s] [ 99%] Linking CXX shared library libsosplugin.so
[  249s] [ 99%] Built target sosplugin
[  250s] make[1]: *** [CMakeFiles/Makefile2:742: src/SOS/Strike/CMakeFiles/sos.dir/all] Error 2
[  250s] make: *** [Makefile:136: all] Error 2
[  250s] Failed to build.

refer to 6b1e6c5