Fix Armel crossgen failing during pack (#45058)

Armel was not treated like arm or arm64, causing the wrong folders to be used during crossgen

Directory.Build.props

@@ -25,6 +25,7 @@
     <_hostArch>$([System.Runtime.InteropServices.RuntimeInformation]::ProcessArchitecture.ToString().ToLowerInvariant)</_hostArch>
     <BuildArchitecture Condition="'$(BuildArchitecture)' == ''">$(_hostArch)</BuildArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(_hostArch)' == 'arm'">arm</TargetArchitecture>
+    <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(_hostArch)' == 'armel'">armel</TargetArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(_hostArch)' == 'arm64'">arm64</TargetArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(TargetOS)' == 'Browser'">wasm</TargetArchitecture>
     <TargetArchitecture Condition="'$(TargetArchitecture)' == '' and '$(TargetsMobile)' == 'true'">x64</TargetArchitecture>

src/coreclr/crossgen-corelib.proj

@@ -24,7 +24,7 @@
       <CrossDir></CrossDir>
     </PropertyGroup>
     <PropertyGroup Condition="'$(BuildArchitecture)' != '$(TargetArchitecture)'">
-      <CrossDir Condition="'$(TargetArchitecture)' == 'arm' or '$(TargetArchitecture)' == 'arm64'">x64</CrossDir>
+      <CrossDir Condition="'$(TargetArchitecture)' == 'arm' or '$(TargetArchitecture)' == 'arm64' or '$(TargetArchitecture)' == 'armel'">x64</CrossDir>
       <CrossDir Condition="'$(TargetArchitecture)' == 'arm' and '$(UseCrossgen2)' != 'true' and '$(OS)' == 'Windows_NT'">x86</CrossDir>
       <CrossDir Condition="'$(TargetArchitecture)' == 'x86' and '$(UseCrossgen2)' == 'true'">$(BuildArchitecture)</CrossDir>
     </PropertyGroup>
@@ -95,7 +95,9 @@
 
       <CrossGenPerfMapCmd>$(CrossGen1Cmd) /CreatePerfMap "$(BinDir)"</CrossGenPerfMapCmd>
       <CrossGenPerfMapCmd>$(CrossGenPerfMapCmd) "$(CoreLibOutputPath)"</CrossGenPerfMapCmd>
+    </PropertyGroup>
 
+    <PropertyGroup Condition="$(BuildPdb) and '$(UseCrossgen2)' != 'true'">
       <CrossGenPdbCmd>$(VsSetupCmd) $(CrossGen1Cmd) /CreatePdb "$([MSBuild]::NormalizePath('$(BinDir)', 'PDB'))"</CrossGenPdbCmd>
       <CrossGenPdbCmd>$(CrossGenPdbCmd) "$(CoreLibOutputPath)"</CrossGenPdbCmd>
     </PropertyGroup>