[tests/codegen/vector_init] Fix qnan matching (#5270)

Author: thewilsonator

tests/codegen/vector_init.d

@@ -4,11 +4,11 @@
 alias D2 = __vector(double[2]);
 
 // CHECK: @{{.*}}_D11vector_init12ImplicitInit6__initZ{{\"?}} =
-// CHECK-SAME: { <2 x double> {{<double 0x7FF8000000000000, double 0x7FF8000000000000>|splat \(double 0x7FF8000000000000\)}} }
+// CHECK-SAME: { <2 x double> {{<double 0x7FF8000000000000, double 0x7FF8000000000000>|splat \(double (0x7FF8000000000000|\+qnan)\)}} }
 struct ImplicitInit { D2 a; }
 
 // CHECK: @{{.*}}_D11vector_init12ExplicitInit6__initZ{{\"?}} =
-// CHECK-SAME: { <2 x double> {{<double 0x7FF8000000000000, double 0x7FF8000000000000>|splat \(double 0x7FF8000000000000\)}} }
+// CHECK-SAME: { <2 x double> {{<double 0x7FF8000000000000, double 0x7FF8000000000000>|splat \(double (0x7FF8000000000000|\+qnan)\)}} }
 struct ExplicitInit { D2 a = D2.init; }
 
 // CHECK: @{{.*}}_D11vector_init10SplatValue6__initZ{{\"?}} =