[build] Remove the mono bundle dependency (#8517)

Context: b830f57
Context: 5daf102
Context: a831d62
Context: 8f33823

All of the dependencies we had on the contents of the mono archive from
commit mono/mono@6dd9def57ce have been removed from main.  We can now
remove all of the xaprepare sources that were used to download, prepare,
and install components from the mono bundle.

.external

@@ -1,2 +1 @@
 xamarin/monodroid:main@c5f1e77bc732dc660090a8d59048f07de846ccd7
-mono/mono:2020-02@6dd9def57ce969ca04a0ecd9ef72c0a8f069112d

Configuration.Override.props.in

@@ -42,6 +42,5 @@
     <!-- These must be FULL PATHS -->
     <AndroidToolchainCacheDirectory>$(HOME)\android-archives</AndroidToolchainCacheDirectory>
     <AndroidToolchainDirectory>$(HOME)\android-toolchain</AndroidToolchainDirectory>
-    <AndroidMxeInstallPrefix>$(AndroidToolchainDirectory)\mxe</AndroidMxeInstallPrefix>
   </PropertyGroup>
 </Project>

Configuration.props

@@ -76,8 +76,6 @@
     <AndroidPreviousFrameworkVersion Condition=" '$(AndroidPreviousFrameworkVersion)' == '' ">v1.0</AndroidPreviousFrameworkVersion>
     <AndroidToolchainCacheDirectory Condition=" '$(AndroidToolchainCacheDirectory)' == '' ">$(HOME)\android-archives</AndroidToolchainCacheDirectory>
     <AndroidToolchainDirectory Condition=" '$(AndroidToolchainDirectory)' == '' ">$(HOME)\android-toolchain</AndroidToolchainDirectory>
-    <AndroidMxeInstallPrefix Condition=" '$(HostOS)' == 'Linux' ">\usr</AndroidMxeInstallPrefix>
-    <AndroidMxeInstallPrefix Condition=" '$(HostOS)' == 'Darwin' ">$(HostHomebrewPrefix)</AndroidMxeInstallPrefix>
     <AndroidSdkDirectory Condition=" '$(AndroidSdkDirectory)' == '' And Exists($(ANDROID_SDK_ROOT)) ">$(ANDROID_SDK_ROOT)</AndroidSdkDirectory>
     <AndroidSdkDirectory Condition=" '$(AndroidSdkDirectory)' == '' ">$(AndroidToolchainDirectory)\sdk</AndroidSdkDirectory>
     <AndroidNdkDirectory Condition=" '$(AndroidNdkDirectory)' == '' And Exists($(ANDROID_NDK_LATEST_HOME)) ">$(ANDROID_NDK_LATEST_HOME)</AndroidNdkDirectory>
@@ -140,7 +138,6 @@
     <Java8SdkDirectory Condition=" '$(Java8SdkDirectory)' == '' ">$(JavaSdkDirectory)</Java8SdkDirectory>
   </PropertyGroup>
   <PropertyGroup>
-    <AndroidMxeFullPath Condition=" '$(AndroidMxeInstallPrefix)' != '' ">$([System.IO.Path]::GetFullPath ('$(AndroidMxeInstallPrefix)'))</AndroidMxeFullPath>
     <AndroidNdkFullPath>$([System.IO.Path]::GetFullPath ('$(AndroidNdkDirectory)'))</AndroidNdkFullPath>
     <AndroidSdkFullPath>$([System.IO.Path]::GetFullPath ('$(AndroidSdkDirectory)'))</AndroidSdkFullPath>
     <JavaInteropFullPath>$([System.IO.Path]::GetFullPath ('$(JavaInteropSourceDirectory)'))</JavaInteropFullPath>

Makefile

@@ -59,18 +59,6 @@ ifneq ($(PREPARE_AUTOPROVISION),0)
 _PREPARE_ARGS += --auto-provision=yes --auto-provision-uses-sudo=yes
 endif
 
-ifeq ($(OS_NAME),Darwin)
-ifeq ($(HOMEBREW_PREFIX),)
-HOMEBREW_PREFIX ?= $(shell brew --prefix)
-endif
-else
-HOMEBREW_PREFIX := $prefix
-endif
-
-ifeq ($(wildcard Configuration.OperatingSystem.props),)
-PREPARE_MSBUILD_FLAGS += "/p:HostHomebrewPrefix=$(HOMEBREW_PREFIX)"
-endif
-
 ifneq ($(PREPARE_SCENARIO),)
 _PREPARE_ARGS += -s:"$(PREPARE_SCENARIO)"
 endif

build-tools/scripts/XAVersionInfo.targets

@@ -6,7 +6,6 @@
   <UsingTask AssemblyFile="$(PrepTasksAssembly)"  TaskName="Xamarin.Android.BuildTools.PrepTasks.GitCommitsInRange" />
   <UsingTask AssemblyFile="$(PrepTasksAssembly)"  TaskName="Xamarin.Android.BuildTools.PrepTasks.GitCommitTime" />
   <UsingTask AssemblyFile="$(PrepTasksAssembly)"  TaskName="Xamarin.Android.BuildTools.PrepTasks.GitCommitInfo" />
-  <Import Project="..\..\bin\Build$(Configuration)\MonoGitHash.props" Condition="Exists('..\..\bin\Build$(Configuration)\MonoGitHash.props')" />
   <Target Name="_GetSubmodulesVersionInfo">
     <ItemGroup>
       <!-- If anything changes in this list, make sure to update:

build-tools/xaprepare/xaprepare/Application/BuildInfo.cs

@@ -22,9 +22,6 @@ partial class BuildInfo : AppObject
 		public string NDKMinimumApiAvailable { get; private set; } = String.Empty;
 
 		public string VersionHash            { get; private set; } = String.Empty;
-		public string MonoHash               { get; private set; } = String.Empty;
-		public string FullMonoHash           { get; private set; } = String.Empty;
-
 		public string XACommitHash           { get; private set; } = String.Empty;
 		public string XABranch               { get; private set; } = String.Empty;
 
@@ -37,8 +34,6 @@ public async Task GatherGitInfo (Context context)
 			Log.StatusLine ("Determining basic build information", ConsoleColor.DarkGreen);
 			await DetermineLastVersionChangeCommit (context);
 			Log.StatusLine ();
-			DetermineMonoHash (context);
-			Log.StatusLine ();
 			DetermineXACommitInfo (context);
 		}
 
@@ -113,31 +108,6 @@ public bool GatherNDKInfo (Context context)
 			return true;
 		}
 
-		void DetermineMonoHash (Context context)
-		{
-			GitRunner git = CreateGitRunner (context);
-
-			Log.StatusLine ($"  {context.Characters.Bullet} Mono commit hash", ConsoleColor.Gray);
-			List<ExternalGitDependency> externalDependencies = ExternalGitDependency.GetDependencies (context, Configurables.Paths.ExternalGitDepsFilePath, quiet: true);
-			ExternalGitDependency? mono = externalDependencies.Where (
-				eg => eg != null &&
-				      String.Compare ("mono", eg.Owner, StringComparison.Ordinal) == 0 &&
-				      String.Compare ("mono", eg.Name, StringComparison.Ordinal) == 0).FirstOrDefault ();
-
-			FullMonoHash = (mono?.Commit ?? String.Empty).Trim ();
-			MonoHash = EnsureHash ("Mono", Utilities.ShortenGitHash (FullMonoHash));
-
-			string EnsureHash (string name, string hash)
-			{
-				if (String.IsNullOrEmpty (hash))
-					throw new InvalidOperationException ($"Unable to determine {name} commit hash");
-				Log.StatusLine ("    Commit: ", hash, tailColor: ConsoleColor.Cyan);
-				Log.StatusLine ();
-
-				return hash;
-			}
-		}
-
 		async Task DetermineLastVersionChangeCommit (Context context)
 		{
 			Log.StatusLine ($"  {context.Characters.Bullet} Commit of last version change", ConsoleColor.Gray);