[release/6.0.1xx] Remove msbuild prebuilts using patches (#12369)

src/SourceBuild/tarball/patches/msbuild/0001-Remove-prebuilt-jnm2.ReferenceAssemblies.net35.patch

@@ -0,0 +1,36 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Davis Goodin <dagood@microsoft.com>
+Date: Mon, 11 Oct 2021 17:09:14 -0500
+Subject: [PATCH] Remove prebuilt jnm2.ReferenceAssemblies.net35
+
+This prebuilt package filled a gap in the official 1.0 version of the .NET
+Framework reference assembly packages. The gap has been fixed in later versions
+of the official packages. Removal fixes a prebuilt dependency by letting the
+repo use the official version of the packges, which are produced by SBRP.
+https://github.com/dotnet/msbuild/issues/6935
+---
+ src/StringTools/StringTools.csproj | 5 -----
+ 1 file changed, 5 deletions(-)
+
+diff --git a/src/StringTools/StringTools.csproj b/src/StringTools/StringTools.csproj
+index fef9909..93a4634 100644
+--- a/src/StringTools/StringTools.csproj
++++ b/src/StringTools/StringTools.csproj
+@@ -20,17 +20,12 @@
+ 
+   <PropertyGroup Condition="'$(TargetFramework)' == 'net35'">
+     <AssemblyName>Microsoft.NET.StringTools.net35</AssemblyName>
+-    <!-- Disable Fx install checks as we're building against jnm2's 3.5 reference assemblies -->
+-    <BypassFrameworkInstallChecks>true</BypassFrameworkInstallChecks>
+   </PropertyGroup>
+ 
+   <ItemGroup Condition="'$(TargetFramework)' != 'net35'">
+     <PackageReference Include="System.Memory" />
+     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" />
+   </ItemGroup>
+-  <ItemGroup>
+-    <PackageReference Include="jnm2.ReferenceAssemblies.net35" PrivateAssets="All" />
+-  </ItemGroup>
+ 
+   <ItemGroup Condition="'$(TargetFramework)' == 'net35'">
+     <Compile Remove="SpanBasedStringBuilder.cs" />

src/SourceBuild/tarball/patches/msbuild/0002-Disable-BannedApiAnalyzers-during-source-build.patch

@@ -0,0 +1,29 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Davis Goodin <dagood@microsoft.com>
+Date: Tue, 12 Oct 2021 18:14:59 -0500
+Subject: [PATCH] Disable BannedApiAnalyzers during source-build
+
+BannedApiAnalyzers has some intentional old dependencies and it's not feasible
+to build it during source-build. Remove this usage to remove a prebuilt.
+https://github.com/dotnet/msbuild/issues/6961
+---
+ eng/Packages.props | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/eng/Packages.props b/eng/Packages.props
+index 0f478634f..3cc09a008 100644
+--- a/eng/Packages.props
++++ b/eng/Packages.props
+@@ -45,11 +45,11 @@
+ 
+   <ItemGroup Condition="'$(DotNetBuildFromSource)' != 'true'">
+     <GlobalPackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All"/>
++    <GlobalPackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="$(MicrosoftCodeAnalysisBannedApiAnalyzersVersion)" />
+   </ItemGroup>
+ 
+   <ItemGroup>
+     <GlobalPackageReference Include="Microsoft.VisualStudio.SDK.EmbedInteropTypes" Version="15.0.15" PrivateAssets="All" Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'" />
+-    <GlobalPackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="$(MicrosoftCodeAnalysisBannedApiAnalyzersVersion)" />
+   </ItemGroup>
+ 
+ </Project>