[test] IRGen: Adjust FileCheck pattern for new initializes attribute in upstream LLVM

The parameter attribute was introduced in
5ece35df8586d0cb8c104a9f44eaae771de025f5 (llvm-project) and is expected
here according to the lowered function body.

Match it using a wildcard regex, since it is not relevant to this test.

This is intended to reduce future conflicts with rebranch.

Author: AnthonyLatsis

validation-test/IRGen/rdar149985633.swift

@@ -2,7 +2,7 @@
 
 // REQUIRES: PTRSIZE=64
 
-// CHECK: define {{.*}}swiftcc void @"$s13rdar1499856334DateV1a1b1c1d1e1fACSiSg_A5JtcfC"(ptr noalias nocapture writeonly sret(%T13rdar1499856334DateV) %0, i64 %1, i8 %2, i64 %3, i8 %4, i64 %5, i8 %6, i64 %7, i8 %8, i64 %9, i8 %10, i64 %11, i8 %12)
+// CHECK: define {{.*}}swiftcc void @"$s13rdar1499856334DateV1a1b1c1d1e1fACSiSg_A5JtcfC"(ptr noalias nocapture writeonly sret(%T13rdar1499856334DateV){{.*}} %0, i64 %1, i8 %2, i64 %3, i8 %4, i64 %5, i8 %6, i64 %7, i8 %8, i64 %9, i8 %10, i64 %11, i8 %12)
 // CHECK: entry:
 // CHECK:   store i64 %1
 // CHECK:   getelementptr inbounds{{.*}} i8, ptr %0, i64 8