Use IsWow64Process2 to determine system architecture (microsoft#5125)

Due to legacy reasons, GetNativeSystemInfo() will return x64 when x86
binaries running on arm64 machines. IsWow64Process2 is the new api
that'll correctly report host machine architecture.

src/AppInstallerCommonCore/Architecture.cpp

@@ -229,22 +229,23 @@ namespace AppInstaller::Utility
     {
         Architecture systemArchitecture = Architecture::Unknown;
 
-        SYSTEM_INFO systemInfo;
-        ZeroMemory(&systemInfo, sizeof(SYSTEM_INFO));
-        GetNativeSystemInfo(&systemInfo);
+        USHORT processArchitecture = IMAGE_FILE_MACHINE_UNKNOWN;
+        USHORT machineArchitecture = IMAGE_FILE_MACHINE_UNKNOWN;
+        // Just log the error if failed and return architecture Unknown.
+        LOG_IF_WIN32_BOOL_FALSE(IsWow64Process2(GetCurrentProcess(), &processArchitecture, &machineArchitecture));
 
-        switch (systemInfo.wProcessorArchitecture)
+        switch (machineArchitecture)
         {
-        case PROCESSOR_ARCHITECTURE_AMD64:
+        case IMAGE_FILE_MACHINE_AMD64:
             systemArchitecture = Architecture::X64;
             break;
-        case PROCESSOR_ARCHITECTURE_ARM:
+        case IMAGE_FILE_MACHINE_ARM:
             systemArchitecture = Architecture::Arm;
             break;
-        case PROCESSOR_ARCHITECTURE_ARM64:
+        case IMAGE_FILE_MACHINE_ARM64:
             systemArchitecture = Architecture::Arm64;
             break;
-        case PROCESSOR_ARCHITECTURE_INTEL:
+        case IMAGE_FILE_MACHINE_I386:
             systemArchitecture = Architecture::X86;
             break;
         }
@@ -276,4 +277,4 @@ namespace AppInstaller::Utility
             return InapplicableArchitecture;
         }
     }
-}
+}