failed to probe do_mmap2 on ppc64

[Li Guanglei <guanglei at cn dot ibm dot com>]

Hi,

  Although gcc won't generate location info for some arguments(in 
fact, most of them) of inlined function, I found that gcc won't even 
generate the location info for some inlined functions themselves. 
do_mmap2 is one example. stap -e 'probe kernel.inline("do_mmap2") {}" 
will fail complaining unable to find do_mmap2.

  using eu-readelf and found gcc doesn't say anything about the 
location info of do_mmap2:

 [ 4ef9a]    subprogram
             sibling              [ 4f015]
             name                 "do_mmap2"
             decl_file            1
             decl_line            161
             prototyped
             type                 [ 48038]
             inline               declared_inlined (3)
...
 [ 4f093]      inlined_subroutine
               abstract_origin      [ 4ef9a]
               ranges               range list [  2440]
               call_file            0
               call_line            0

 I looked at gcc bug 23551 yet to find it's still far away to get 
such bugs of inlined functions to be fixed.

- Guanglei