Hello, I'm using Msys2 MinGW Clang++ to build cryptopp.
When I did the make command, I got this error:

```bash
C:/msys64/mingw64/bin/ld: ./libcryptopp.a(cpu.o): in function `CryptoPP::XGetBV(unsigned int)':
D:/cryptopp890/cpu.cpp:395:(.text+0x11): undefined reference to `XGETBV64'
C:/msys64/mingw64/bin/ld: ./libcryptopp.a(cpu.o): in function `CryptoPP::CpuId(unsigned int, unsigned int, unsigned int*)':
D:/cryptopp890/cpu.cpp:453:(.text+0x25): undefined reference to `CPUID64'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [GNUmakefile:1511: cryptest.exe] Error 1
```

Do you know how to fix it or can you give me the some instruction for me, I have an assignments about this so please help me. Thank you
Linker command
This is a GitHub Issue
repo:cryptopp
owner:weidai11
Title : Linker command
Issue date:

--- start body ---
Hello, I'm using Msys2 MinGW Clang++ to build cryptopp.
When I did the make command, I got this error:

```bash
C:/msys64/mingw64/bin/ld: ./libcryptopp.a(cpu.o): in function `CryptoPP::XGetBV(unsigned int)':
D:/cryptopp890/cpu.cpp:395:(.text+0x11): undefined reference to `XGETBV64'
C:/msys64/mingw64/bin/ld: ./libcryptopp.a(cpu.o): in function `CryptoPP::CpuId(unsigned int, unsigned int, unsigned int*)':
D:/cryptopp890/cpu.cpp:453:(.text+0x25): undefined reference to `CPUID64'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [GNUmakefile:1511: cryptest.exe] Error 1
```

Do you know how to fix it or can you give me the some instruction for me, I have an assignments about this so please help me. Thank you
--- end body ---
