hg: jdk8u/jdk8u/hotspot: 8269468: JDK-8269388 breaks the build on older GCCs

[gnu.andrew at redhat.com]

Changeset: 78dfe32cac58
Author:    andrew
Date:      2021-06-28 19:46 +0100
URL:       https://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/rev/78dfe32cac58

8269468: JDK-8269388 breaks the build on older GCCs
Summary: Only set -Wno-error=format-overflow when -Wformat-overflow is supported
Reviewed-by: aph, sgehwolf

! make/linux/makefiles/gcc.make