Register Zig Compiler tool (KhronosGroup#405)

Author: Snektron

include/spirv/spir-v.xml

@@ -91,7 +91,8 @@
         <id value="38"  vendor="Meta" tool="SparkSL" comment="Contact Dunfan Lu, [email protected], https://sparkar.facebook.com/ar-studio/learn/sparksl/sparksl-overview"/>
         <id value="39"  vendor="SirLynix" tool="Nazara ShaderLang Compiler" comment="Contact Jérôme Leclercq, https://github.com/NazaraEngine/ShaderLang"/>
         <id value="40"  vendor="NVIDIA" tool="Slang Compiler" comment="Contact Theresa Foley, [email protected], https://github.com/shader-slang/slang/"/>
-        <unused start="41" end="0xFFFF" comment="Tool ID range reservable for future use by vendors"/>
+        <id value="41"  vendor="Zig Software Foundation" tool="Zig Compiler" comment="Contact Robin Voetter, https://github.com/Snektron"/>
+        <unused start="42" end="0xFFFF" comment="Tool ID range reservable for future use by vendors"/>
     </ids>
 
     <!-- SECTION: SPIR-V Opcodes and Enumerants -->