Implemented a stripped down (and so far untested)
dladdr()-implementation
using AIX' own loadquery()-function. Following the SGI example in the
same
code, the DL_info only has the dli_fname member. As the scope of
dlfcn_pathbyaddr() is the filename, this implementation does not
consider
archive members, which can be dlopen()ed in AIX. It is also leaking
memory
as it provides a copy of ldinfo_filename.

Signed-off-by: Matthias Kraft <[email protected]>

Fixed thinko in calculation of next ld_info entry. Changed to large
fixed
size ld_info buffer, as the ld_info entries are of dynamic size. The 80k
will still hold 32 entries in a worst case scenario.
The implementation can only lookup function symbols, no data symbols.
Added PIC-flag to aix*-cc build targets.
The marked printf's will be removed when the test case is implemented.

Added DATA segment checking to catch ptrgl virtual addresses. Avoid
memleaks with every AIX/dladdr() call. Removed debug-fprintf()s.
Added test case for DSO_dsobyaddr(), which will eventually call dladdr().
Removed unecessary AIX ifdefs again.

Fixed indentation, moved trailing operators to leading and removed
unecessary braces. Tried to sqeeze everything in 80 cpl.
Removed extra errno declaration. Changed a void* into char* for
portable pointer arithmetics.
Addressed a Travis issue complaining about another void*-cast.
Reconfigured the test code to be empty on Windows, as the implementation
there is completely different and would always produce an error. This is
addressing the Appveyor issue.

Although it deviates from the actual prototype of DSO_dsobyaddr(), this
is now ISO C compliant and gcc -Wpedantic accepts the code.

Removed architecture dependent comment, not really belonging here.
More style guide conformance edits, partly indent suggested.