Add -D__ANDROID_NATIVE_BRIDGE__ to native_bridge targets

And remove dual meaning from arm_on_x86 target. It was set for x86
targets with arm support and for arm targets with x86 support - and that
2nd one was abused for native_bridge version of RenderScript.

It's much safer and cleaner to rely on __ANDROID_NATIVE_BRIDGE__ there
while leaving arm_on_x86 to mean "x86 binary built in the image with arm
support".

It's only used by bcc compiler which is in canadian-cross situation here:
it's pure x86-64 binary, but it needs to know about ALL supported
architectures on device because it needs to include appropriate codegen
module.

Bug: http://b/153609531

Test: cts-tradefed run cts --abi armeabi-v7a -m CtsRsCppTestCases
Test: cts-tradefed run cts --abi arm64-v8a -m CtsRsCppTestCases

Change-Id: I869212e0b82eeaa30361a4e183d5c862ab40ef12
diff --git a/android/arch.go b/android/arch.go
index 9a54614..a99915f 100644
--- a/android/arch.go
+++ b/android/arch.go
@@ -1396,20 +1396,15 @@
 			//         key: value,
 			//     },
 			// },
-			// TODO(ccross): is this still necessary with native bridge?
 			if os.Class == Device {
-				if (arch.ArchType == X86 && (hasArmAbi(arch) ||
-					hasArmAndroidArch(ctx.Config().Targets[Android]))) ||
-					(arch.ArchType == Arm &&
-						hasX86AndroidArch(ctx.Config().Targets[Android])) {
+				if arch.ArchType == X86 && (hasArmAbi(arch) ||
+					hasArmAndroidArch(ctx.Config().Targets[Android])) {
 					field := "Arm_on_x86"
 					prefix := "target.arm_on_x86"
 					m.appendProperties(ctx, genProps, targetProp, field, prefix)
 				}
-				if (arch.ArchType == X86_64 && (hasArmAbi(arch) ||
-					hasArmAndroidArch(ctx.Config().Targets[Android]))) ||
-					(arch.ArchType == Arm &&
-						hasX8664AndroidArch(ctx.Config().Targets[Android])) {
+				if arch.ArchType == X86_64 && (hasArmAbi(arch) ||
+					hasArmAndroidArch(ctx.Config().Targets[Android])) {
 					field := "Arm_on_x86_64"
 					prefix := "target.arm_on_x86_64"
 					m.appendProperties(ctx, genProps, targetProp, field, prefix)
@@ -1556,27 +1551,7 @@
 // hasArmArch returns true if targets has at least non-native_bridge arm Android arch
 func hasArmAndroidArch(targets []Target) bool {
 	for _, target := range targets {
-		if target.Os == Android && target.Arch.ArchType == Arm && target.NativeBridge == NativeBridgeDisabled {
-			return true
-		}
-	}
-	return false
-}
-
-// hasX86Arch returns true if targets has at least x86 Android arch
-func hasX86AndroidArch(targets []Target) bool {
-	for _, target := range targets {
-		if target.Os == Android && target.Arch.ArchType == X86 {
-			return true
-		}
-	}
-	return false
-}
-
-// hasX8664Arch returns true if targets has at least x86_64 Android arch
-func hasX8664AndroidArch(targets []Target) bool {
-	for _, target := range targets {
-		if target.Os == Android && target.Arch.ArchType == X86_64 {
+		if target.Os == Android && target.Arch.ArchType == Arm {
 			return true
 		}
 	}