hg: jdk/sandbox: 8227397: Add --with-extra-asflags configure option

[chris.hegarty at oracle.com]

Changeset: c6923eaecd7b
Author:    sgehwolf
Date:      2019-07-08 17:44 +0200
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/c6923eaecd7b

8227397: Add --with-extra-asflags configure option
Reviewed-by: phh

! make/autoconf/flags.m4
! make/autoconf/spec.gmk.in
! make/hotspot/lib/CompileJvm.gmk