Only set path in x64 mac installer when installing on x64

In other words don't set the path for x64 installer on ARM64

src/installer/pkg/sfx/installers/dotnet-host.proj

@@ -16,6 +16,7 @@
     <MacOSComponentNamePackType>sharedhost</MacOSComponentNamePackType>
     <IncludeVersionInMacOSComponentName>false</IncludeVersionInMacOSComponentName>
     <MacOSScriptsDirectory>osx_scripts/host</MacOSScriptsDirectory>
+    <MacOSScriptsDirectory Condition="'$(TargetArchitecture)' == 'x64">osx_scripts/host-x64</MacOSScriptsDirectory>
     <MacOSPackageDescription>The .NET Shared Host.</MacOSPackageDescription>
     <RpmScriptsDirectory>$(MSBuildThisFileDirectory)rpm_scripts/host</RpmScriptsDirectory>
     <RpmAfterInstallScript>$(RpmScriptsDirectory)/after_install.sh</RpmAfterInstallScript>

src/installer/pkg/sfx/installers/dotnet-hostfxr.proj

@@ -14,7 +14,8 @@
     <OutputFilesCandleVariable>HostFxrSrc</OutputFilesCandleVariable>
     <UseBrandingNameInLinuxPackageDescription>true</UseBrandingNameInLinuxPackageDescription>
     <MacOSComponentNamePackType>hostfxr</MacOSComponentNamePackType>
-    <MacOSScriptsDirectory>osx_scripts/hostfxr</MacOSScriptsDirectory>
+    <MacOSScriptsDirectory>osx_scripts/host</MacOSScriptsDirectory>
+    <MacOSScriptsDirectory Condition="'$(TargetArchitecture)' == 'x64">osx_scripts/host-x64</MacOSScriptsDirectory>
     <MacOSPackageDescription>The .NET HostFxr</MacOSPackageDescription>
   </PropertyGroup>
 

src/installer/pkg/sfx/installers/osx_scripts/host-x64/postinstall

@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# Licensed to the .NET Foundation under one or more agreements.
+# The .NET Foundation licenses this file to you under the MIT license.
+#
+
+PACKAGE=$1
+INSTALL_DESTINATION=$2
+
+_machine=`uname -m`
+
+# A temporary fix for the permissions issue(s)
+chmod 755 $INSTALL_DESTINATION/dotnet
+
+if ["$_machine" == "amd64"] || ["$_machine" == "x86_x64"]; then
+    # Add the installation directory to the system-wide paths
+    # But first create the directory if it doesn't exist
+    mkdir -p /etc/paths.d
+    echo $INSTALL_DESTINATION | tee /etc/paths.d/dotnet
+fi
+
+exit 0