std.Target: Fix ptrBitWidth_cpu_abi() for dxil (64-bit, not 32-bit).

The DXIL documentation claims 32-bit pointers:

https://github.com/microsoft/DirectXShaderCompiler/blob/main/docs/DXIL.rst#memory-accesses

Despite this, Clang considers pointers 64-bit when targeting it.

lib/std/Target.zig

@@ -1854,12 +1854,12 @@ pub fn ptrBitWidth_cpu_abi(cpu: Cpu, abi: Abi) u16 {
         .wasm32,
         .spirv32,
         .loongarch32,
-        .dxil,
         .xtensa,
         => 32,
 
         .aarch64,
         .aarch64_be,
+        .dxil,
         .mips64,
         .mips64el,
         .powerpc64,