Add Xcode 12.2 and 12.3 beta (#2054)

images/macos/provision/core/xcode-clt.sh

@@ -11,12 +11,7 @@ install_clt() {
     # This temporary file prompts the 'softwareupdate' utility to list the Command Line Tools
     clt_placeholder="/tmp/.com.apple.dt.CommandLineTools.installondemand.in-progress"
     sudo touch $clt_placeholder
-    # The only working tools for Big Sur are 12.2
-    if is_Less_BigSur; then
-        cltPattern="Command Line Tools"
-    else
-        cltPattern="Command Line Tools.*Xcode-12.2"
-    fi
+    cltPattern="Command Line Tools"
 
     clt_label_command="/usr/sbin/softwareupdate -l |
                         grep -B 1 -E '${cltPattern}' |

images/macos/toolsets/toolset-10.15.json

@@ -2,7 +2,7 @@
     "xcode": {
         "default": "12",
         "versions": [
-            "12.2_Release_Candidate", "12.1.1_Release_Candidate", "12.1", "12", "11.7", "11.6", "11.5", "11.4.1", "11.3.1", "11.2.1", "10.3"
+            "12.3_beta", "12.2", "12.1.1_Release_Candidate", "12.1", "12", "11.7", "11.6", "11.5", "11.4.1", "11.3.1", "11.2.1", "10.3"
         ]
     },
     "xamarin": {

images/macos/toolsets/toolset-11.0.json

@@ -2,7 +2,7 @@
     "xcode": {
         "default": "11.7",
         "versions": [
-            "12.2_Release_Candidate", "11.7"
+            "12.3_beta", "12.2", "11.7"
         ]
     },
     "xamarin": {