meson: Prefix each element of firmware path

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20220624154042.51512-1-akihiko.odaki@gmail.com>
[Rewrite shell function without using Bash extensions. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

configure

@@ -676,6 +676,21 @@ fi
 
 werror=""
 
+meson_option_build_array() {
+  printf '['
+  (if test "$targetos" == windows; then
+    IFS=\;
+  else
+    IFS=:
+  fi
+  for e in $1; do
+    e=${e/'\'/'\\'}
+    e=${e/\"/'\"'}
+    printf '"""%s""",' "$e"
+  done)
+  printf ']\n'
+}
+
 . $source_path/scripts/meson-buildoptions.sh
 
 meson_options=