hg: jdk/submit: 8205197: Never default to using libc++ on Linux

[martinrb at google.com]

Changeset: 3ffe45980968
Author:    martin
Date:      2018-06-21 19:50 -0700
URL:       http://hg.openjdk.java.net/jdk/submit/rev/3ffe45980968

8205197: Never default to using libc++ on Linux
Summary: Let the toolchain choose the standard library by default
Reviewed-by: tbell, erikj, gziemski

! make/autoconf/flags-ldflags.m4