Remove explicit target(s) from reflect_empty_struct tests

Swift CI tests backward deployment on different host OSes, so this should be covered in
testing. The explicit target doesn't work well with `executable_test` since it leads to
binaries with too-new minimum deployment targets getting executed on older host OSes.

Author: jckarter

validation-test/Reflection/reflect_empty_struct.swift

@@ -1,5 +1,5 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-build-swift -lswiftSwiftReflectionTest -I %S/Inputs/EmptyStruct/ %s -o %t/reflect_empty_struct -target x86_64-apple-macosx10.99.0
+// RUN: %target-build-swift -lswiftSwiftReflectionTest -I %S/Inputs/EmptyStruct/ %s -o %t/reflect_empty_struct
 // RUN: %target-codesign %t/reflect_empty_struct
 
 // RUN: %target-run %target-swift-reflection-test %t/reflect_empty_struct | %FileCheck %s --check-prefix=CHECK-%target-ptrsize --dump-input fail
@@ -32,13 +32,13 @@ reflect(object: obj)
 // CHECK-64: Type info:
 // CHECK-64: (class_instance size=80 alignment=8 stride=80 num_extra_inhabitants=0 bitwise_takable=1
 // CHECK-64:   (field name=a offset=16
-// CHECK-64:     (builtin size=0 alignment=1 stride=1 num_extra_inhabitants=0 bitwise_takable=1))
+// CHECK-64:     ({{builtin|struct}} size=0 alignment={{1|4}} stride=1 num_extra_inhabitants=0 bitwise_takable=1))
 // CHECK-64:   (field name=b offset=16
 // CHECK-64:     (opaque_existential size=32 alignment=8 stride=32 num_extra_inhabitants=2147483647 bitwise_takable=1
 // CHECK-64:       (field name=metadata offset=24
 // CHECK-64:         (builtin size=8 alignment=8 stride=8 num_extra_inhabitants=2147483647 bitwise_takable=1))))
 // CHECK-64:   (field name=c offset=48
-// CHECK-64:     (builtin size=0 alignment=4 stride=1 num_extra_inhabitants=0 bitwise_takable=1))
+// CHECK-64:     ({{builtin|struct}} size=0 alignment={{1|4}} stride=1 num_extra_inhabitants=0 bitwise_takable=1))
 // CHECK-64:   (field name=d offset=48
 // CHECK-64:     (opaque_existential size=32 alignment=8 stride=32 num_extra_inhabitants=2147483647 bitwise_takable=1
 // CHECK-64:       (field name=metadata offset=24
@@ -52,13 +52,13 @@ reflect(object: obj)
 // CHECK-32: Type info:
 // CHECK-32: (class_instance size=40 alignment=4 stride=40 num_extra_inhabitants=0 bitwise_takable=1
 // CHECK-32:   (field name=a offset=8
-// CHECK-32:     (builtin size=0 alignment=1 stride=1 num_extra_inhabitants=0 bitwise_takable=1))
+// CHECK-32:     ({{builtin|struct}} size=0 alignment={{1|4}} stride=1 num_extra_inhabitants=0 bitwise_takable=1))
 // CHECK-32:   (field name=b offset=8
 // CHECK-32:     (opaque_existential size=16 alignment=4 stride=16 num_extra_inhabitants=4096 bitwise_takable=1
 // CHECK-32:       (field name=metadata offset=12
 // CHECK-32:         (builtin size=4 alignment=4 stride=4 num_extra_inhabitants=4096 bitwise_takable=1))))
 // CHECK-32:   (field name=c offset=24
-// CHECK-32:     (builtin size=0 alignment=4 stride=1 num_extra_inhabitants=0 bitwise_takable=1))
+// CHECK-32:     ({{builtin|struct}} size=0 alignment={{1|4}} stride=1 num_extra_inhabitants=0 bitwise_takable=1))
 // CHECK-32:   (field name=d offset=24
 // CHECK-32:     (opaque_existential size=16 alignment=4 stride=16 num_extra_inhabitants=4096 bitwise_takable=1
 // CHECK-32:       (field name=metadata offset=12

validation-test/Reflection/reflect_empty_struct_compat.swift

@@ -1,10 +1,6 @@
 // RUN: %empty-directory(%t)
 
-// RUN: %target-build-swift -lswiftSwiftReflectionTest -I %S/Inputs/EmptyStruct/ %s -o %t/reflect_empty_struct -target x86_64-apple-macosx10.15.0
-// RUN: %target-codesign %t/reflect_empty_struct
-// RUN: %target-run %target-swift-reflection-test %t/reflect_empty_struct | %FileCheck %s --check-prefix=CHECK-%target-ptrsize --dump-input fail
-
-// RUN: %target-build-swift -lswiftSwiftReflectionTest -I %S/Inputs/EmptyStruct/ %s -o %t/reflect_empty_struct -target x86_64-apple-macosx10.14.0
+// RUN: %target-build-swift -lswiftSwiftReflectionTest -I %S/Inputs/EmptyStruct/ %s -o %t/reflect_empty_struct
 // RUN: %target-codesign %t/reflect_empty_struct
 // RUN: %target-run %target-swift-reflection-test %t/reflect_empty_struct | %FileCheck %s --check-prefix=CHECK-%target-ptrsize --dump-input fail