S390 has several load and store instructions with target operand
addressing relative to the program counter, for example lrl, lgrl, strl,
stgrl.

These instructions are handled similar to x86. Objdump output displays
those instructions as:

   9595c: c4 2d 00 09 9c 54   lgrl   %r7,1c8540 <mp_+0x60>

This output is parsed (like on x86) and perf annotate shows those lines
as:

   lgrl   %r7,mp_+0x60

This patch handles the s390 specific instruction parsing for PC relative
load and store instructions.
Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308120913.14802-1-tmricht@linux.vnet.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>