Disable legacy_backend jits

[tfs-changeset: 1692827]


Commit migrated from dotnet/coreclr@5a281a4

src/coreclr/src/jit/DIRS.proj

@@ -25,9 +25,13 @@
   <!-- Only the main JIT gets built for CoreSys. The other jits (e.g., altjits) do not. -->
   <ItemGroup Condition="'$(BuildExePhase)' == '1' and '$(BuildProjectName)' != 'CoreSys'">
 
+    <!-- FrankenJit and FrankenAltJit builds are disabled. We do not test them in CoreCLR and changes from there regularly break legacy_bakend for x86, it is why it is disabled now
+         and should be completely deleted soon. -->
     <!-- Build the "FrankenJit" (RyuJIT front-end, legacy back-end) and "FrankenAltjit". These can't conflict with the names of the JIT32 directory outputs. -->
+    <!-- 
     <ProjectFile Condition="'$(BuildArchitecture)' == 'i386' or '$(BuildArchitecture)' == 'arm'"  Include="frankenjit\frankenjit.nativeproj" />
     <ProjectFile Condition="'$(BuildArchitecture)' == 'i386'" Include="frankenaltjit\frankenaltjit.nativeproj" />
+    -->
 
     <!-- This might be useful, to help make sure JIT devs build all configurations of the JIT (including crossgen), but
          it appears to cause problems with the build system, and it slows down normal JIT developer productivity by adding a seldom-useful build.