[Bug libgomp/65155] New: libgomp-plugin-host_nonshm installation failure

[dje at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65155

            Bug ID: 65155
           Summary: libgomp-plugin-host_nonshm installation failure
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dje at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org

Installation of libgomp-plugin-host_nonshm fails because of relinking. 
libgomp-plugin-host_nonshm.la contains a "relink" command because libtool is
invoked with --tag disatable-static.  However, the plugin somehow is in use
during the linking process.

libtool: relink: /home/dje/build/20150218/./gcc/xgcc
-B/home/dje/build/20150218/./gcc/
-B/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/powerpc-ibm-aix7.1.2.0/bin/
-B/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/powerpc-ibm-aix7.1.2.0/lib/
-isystem
/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/powerpc-ibm-aix7.1.2.0/include
-isystem
/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/powerpc-ibm-aix7.1.2.0/sys-include
   -shared -o .libs/libgomp-plugin-host_nonshm.so.1 
.libs/libgomp_plugin_host_nonshm_la-plugin-host.o  
-Wl,-blibpath:/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/lib:/home/dje/build/20150218/./gcc:/usr/lib:/lib
-L/home/dje/install/powerpc-ibm-aix7.1.2.0-20150218/lib -lgomp -lpthread -ldl
-lc -Wl,-bnoentry  -pthread   -Wl,-bE:.libs/libgomp-plugin-host_nonshm.exp
-Wl,-berok
ld: 0711-851 SEVERE ERROR: Output file: .libs/libgomp-plugin-host_nonshm.so.1
        The file is in use and cannot be overwritten.
collect2: error: ld returned 12 exit status

I am not sure how the plugin shared object is being referenced, but that seems
like a bug.

Possible solutions:

1) Don't reference the shared object unnecessarily.
2) Don't generate relink command for libtool
3) Ignore relink command on AIX (like cygwin?)
4) Relink should delete shared object before trying to regenerate it.