Merge pull request dotnet/coreclr#7918 from RussKeldorph/repoint-corefx-1.1.0

Make dotnet/coreclr reference corresponding dotnet/corefx branch

Commit migrated from https://github.com/dotnet/coreclr/commit/f3c19d782ae9d2575cedd9f1a8c2e2bdc081200e

diff --cc src/coreclr/netci.groovy
index d46c496,7a64274..3bba51d
--- 1/src/coreclr/netci.groovy
--- 2/src/coreclr/netci.groovy
+++ b/src/coreclr/netci.groovy
@@@ -2008,10 -1729,10 +2008,10 @@@ combinedScenarios.each { scenario -
                                          buildCommands += "rm -rf .clr; mkdir .clr; mv * .clr; mv .git .clr; mv .clr clr"
                                          
                                          // Get corefx
-                                         buildCommands += "git clone https://github.com/dotnet/corefx fx"
+                                         buildCommands += "git clone -b $branch --single-branch https://github.com/dotnet/corefx fx"
                                          
                                          // Set environment variable
 -                                        def setEnvVar = getStressModeEnvSetCmd(os, scenario)                                        
 +                                        def setEnvVar = getStressModeEnvSetCmd(os, scenario)
  
                                          // Build and text corefx
                                          buildCommands += "rm -rf \$WORKSPACE/fx_home; mkdir \$WORKSPACE/fx_home"