gollvm: add "ios", "zos" to supported GOOS values

Add "ios" and "zos" to the set of supported GOOS values, now needed as
part of the update of gofrontend to Go1.16beta1.

Updates golang/go#43540.

Change-Id: Ifb5fb281f4fec1aca9f934ceeded4a719728a103
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/281855
Trust: Than McIntosh <thanm@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/cmake/modules/GoVars.cmake b/cmake/modules/GoVars.cmake
index ec6f6b2..5aa2c32 100644
--- a/cmake/modules/GoVars.cmake
+++ b/cmake/modules/GoVars.cmake
@@ -18,7 +18,7 @@
 # List of all architectures, families, os flavors.
 set(allgoarch "386" "alpha" "amd64" "amd64p32" "arm" "armbe" "arm64" "arm64be" "ia64" "m68k" "mips" "mipsle" "mips64" "mips64le" "mips64p32" "mips64p32le" "nios2" "ppc" "ppc64" "ppc64le" "riscv" "riscv64" "s390" "s390x" "sh" "shbe" "sparc" "sparc64" "wasm")
 set(allgoarchfamily "I386" "ALPHA" "AMD64" "ARM" "ARM64" "IA64" "M68K" "MIPS" "MIPS64" "PPC" "PPC64" "RISCV" "RISCV64" "S390" "S390X" "SH" "SPARC" "SPARC64" "WASM")
-set(allgoos "aix" "android" "darwin" "dragonfly" "freebsd" "irix" "linux" "netbsd" "openbsd" "plan9" "rtems" "solaris" "windows")
+set(allgoos "aix" "android" "darwin" "dragonfly" "freebsd" "ios" "irix" "linux" "netbsd" "openbsd" "plan9" "rtems" "solaris" "windows" "zos")
 
 # Set library suffix based on target triple
 if( ${llarch} STREQUAL "x86_64" )