Shim can have more names, shim 15.8 comes as BOOT*.EFI

https://bugs.gentoo.org/968277

--- a/refind-install
+++ b/refind-install
@@ -385,7 +385,8 @@
    echo "ShimSource is $ShimSource"
    if [[ "$ShimSource" != "none" ]] ; then
       if [[ -f "$ShimSource" ]] ; then
-         if [[ $ShimType == "shimx64.efi" || $ShimType == "shim.efi" || $ShimType == "shimx64.efi.signed" ]] ; then
+         if [[ $ShimType == "shimx64.efi" || $ShimType == "shim.efi" || $ShimType == "shimx64.efi.signed" ||
+		 $ShimType == "BOOTX64.EFI" || $ShimType == "BOOTIA32.EFI" ]] ; then
             TargetX64="grubx64.efi"
             TargetAARCH64="grubaa64.efi"
             MokManagerSource=$(dirname "$ShimSource")/mm$Platform.efi.signed
@@ -400,7 +401,7 @@
             MokManagerSource=$(dirname "$ShimSource")/HashTool.efi
          else
             echo "Unknown shim/PreBootloader filename: $ShimType!"
-            echo "Known filenames are shimx64.efi, shim.efi, and PreLoader.efi. Aborting!"
+            echo "Known filenames are shimx64.efi, shim.efi, BOOTX64.EFI, BOOTIA32.EFI, and PreLoader.efi. Aborting!"
             exit 1
          fi
       else