Merge commit '434b44cd6fb4bb9a2bf2bb29ef55ce1a315314b8'

* commit '434b44cd6fb4bb9a2bf2bb29ef55ce1a315314b8':
  configure: Simplify vararg check

Merged-by: James Almer <jamrial@gmail.com>

configure

@@ -5435,12 +5435,11 @@ fi
 check_gas() {
     log "check_gas using '$as' as AS"
     # :vararg is used on aarch64, arm and ppc altivec
-    test_as <<EOF || return 1
+    check_as vararg "
 .macro m n, y:vararg=0
 \n: .int \y
 .endm
-m x
-EOF
+m x" || return 1
     # .altmacro is only used in arm asm
     ! enabled arm || check_as gnu_as ".altmacro"
 }