IRGen: Fix test case only on x86-64 do we use indirect byval passing

Author: aschwaighofer

test/IRGen/c_functions.swift

@@ -1,5 +1,6 @@
 // RUN: %empty-directory(%t)
 // RUN: %target-swift-frontend -assume-parsing-unqualified-ownership-sil -import-objc-header %S/Inputs/c_functions.h -primary-file %s -emit-ir | %FileCheck %s
+// RUN: %target-swift-frontend -assume-parsing-unqualified-ownership-sil -target x86_64-apple-macosx10.11 -import-objc-header %S/Inputs/c_functions.h -primary-file %s -emit-ir |  %FileCheck %s --check-prefix=x86_64
 
 // This is deliberately not a SIL test so that we can test SILGen too.
 
@@ -18,8 +19,8 @@ func test_indirect_by_val_alignment() {
   log_a_thing(x)
 }
 
-// CHECK-LABEL: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
-// CHECK: %indirect-temporary = alloca %TSC7a_thingV, align [[ALIGN:[0-9]+]]
-// CHECK: [[CAST:%.*]] = bitcast %TSC7a_thingV* %indirect-temporary to %struct.a_thing*
-// CHECK: call void @log_a_thing(%struct.a_thing* byval align [[ALIGN]] [[CAST]])
-// CHECK: define internal void @log_a_thing(%struct.a_thing* byval align [[ALIGN]]
+// x86_64-LABEL: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
+// x86_64: %indirect-temporary = alloca %TSC7a_thingV, align [[ALIGN:[0-9]+]]
+// x86_64: [[CAST:%.*]] = bitcast %TSC7a_thingV* %indirect-temporary to %struct.a_thing*
+// x86_64: call void @log_a_thing(%struct.a_thing* byval align [[ALIGN]] [[CAST]])
+// x86_64: define internal void @log_a_thing(%struct.a_thing* byval align [[ALIGN]]