Fix test to also run on linux

Author: aschwaighofer

test/IRGen/c_functions.swift

@@ -1,6 +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
+// RUN: %target-swift-frontend -assume-parsing-unqualified-ownership-sil -import-objc-header %S/Inputs/c_functions.h -primary-file %s -emit-ir |  %FileCheck %s --check-prefix=%target-cpu
 
 // This is deliberately not a SIL test so that we can test SILGen too.
 
@@ -24,3 +24,11 @@ func test_indirect_by_val_alignment() {
 // 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]]
+
+
+// We only want to test x86_64.
+// arm64: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
+// armv7k: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
+// armv7s: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
+// armv7: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()
+// i386: define hidden swiftcc void  @_T011c_functions30test_indirect_by_val_alignmentyyF()