Change intrinsics config to avoid shani/avx512 by default.

Author: evoskuil

builds/msvc/vs2022/libbitcoin-system.import.props

@@ -14,15 +14,15 @@
   <!-- Options -->
 
   <!-- These create non-portability. -->
+  <!-- These will compile to the target regardless of the compiling platform. -->
+  <!-- That will result in a crash of test/executable execution if mismatched. -->
   <PropertyGroup>
-    <Option-avx512>true</Option-avx512>
+    <Option-avx512>false</Option-avx512>
     <Option-avx2>true</Option-avx2>
     <Option-sse41>true</Option-sse41>
-    <Option-shani>true</Option-shani>
+    <Option-shani>false</Option-shani>
     <Option-neon>false</Option-neon>
   </PropertyGroup>
-  
-  <!-- These create non-portability. -->
   <ItemDefinitionGroup>
     <ClCompile>
       <!-- order matters -->