hg: jdk/jdk: 8238281: Raise minimum gcc version needed to 5.0

[magnus.ihse.bursie at oracle.com]

Changeset: 932418820c80
Author:    ihse
Date:      2020-02-05 10:45 +0100
URL:       https://hg.openjdk.java.net/jdk/jdk/rev/932418820c80

8238281: Raise minimum gcc version needed to 5.0
Reviewed-by: erikj, dholmes, jwilhelm, mbaesken

! doc/building.html
! doc/building.md
! make/autoconf/flags-cflags.m4
! make/autoconf/flags.m4
! make/autoconf/toolchain.m4
! make/hotspot/lib/CompileJvm.gmk
! src/hotspot/share/memory/operator_new.cpp
! src/hotspot/share/prims/jvm.cpp
! src/hotspot/share/utilities/compilerWarnings_gcc.hpp
! src/hotspot/share/utilities/debug.hpp
! src/hotspot/share/utilities/globalDefinitions_gcc.hpp
! src/hotspot/share/utilities/ostream.cpp