rules.mak: Also try -r to build modules

rules.mak: Also try -r to build modules

Building qemu fails in distributions where gcc enables PIE by default
(e.g. Debian unstable) with:

/usr/bin/ld: -r and -pie may not be used together

You have to use -r instead of -Wl,-r to avoid gcc passing -pie to the linker
when PIE is enabled and a relocatable object is passed.  However, clang
does not know about -r, so try -Wl,-r first.

[This is a fix for commit c96f0ee6a67ca6277366e78ce5d84d5c20dd596f
("rules.mak: Use -r instead of -Wl, -r to fix building when PIE is
default") which mostly worked but broke the ./configure --enable-modules
build with clang.
--Stefan]

Reported-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161129153720.29747-1-pbonzini@redhat.com
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>