[build.ps1] remove Android API level from Dispatch.swiftmodule names

[andrurogerz]

Purpose

When determining output paths for Android binaries in the SDK, ensure that the Android API level integer is not included in paths. E.g. use the versionless "module triple" aarch64-unknown-linux-android instead of aarch64-unknown-linux-android28.

Overview

• Add a new Get-TargetInfo $Arch method that returns the result of swift.exe -target $Arch.LLVMTarget -print-target-info as parsed JSON object using the newly built toolchain
  • Cache the result in the $Arch hashtable to avoid making multiple calls
• Add a new Get-ModuleTriple $Arch method that calls Get-TargetInfo $Arch and returns the resulting .target.moduleTriple string
• Use Get-ModuleTriple to calculate the target path in Install-Platform when copying .swiftmodule, .swiftdoc, and .swiftinterface files (this case includes Dispatch.swiftmodule).
• Replace existing calls to $Arch.LLVMTarget.Replace("$AndroidAPILevel","") with a Get-ModuleTriple $Arch

Validation

Local toolchain build with -AndroidSDKs aarch64,x86_64 and verified the expected directory structure of the Dispatch module in the Android SDK:

S:\Program Files>dir /s /b "S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule"
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\aarch64-unknown-linux-android.swiftdoc
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\aarch64-unknown-linux-android.swiftmodule
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\armv7-unknown-linux-android.swiftdoc
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\armv7-unknown-linux-android.swiftmodule
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\i686-unknown-linux-android.swiftdoc
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\i686-unknown-linux-android.swiftmodule
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\x86_64-unknown-linux-android.swiftdoc
S:\Program Files\Swift\Platforms\Android.platform\Developer\SDKs\Android.sdk\usr\lib\swift\android\Dispatch.swiftmodule\x86_64-unknown-linux-android.swiftmodule

Successfully built this simple Swift program for Android using the locally built SDK.

[compnerd]

@swift-ci please smoke test

[compnerd]

@swift-ci please test