Use -bnoipath on vacpp/AIX.

Patch from Etienne PIERRE. Fixes #2843.


[SVN r51697]

v2/tools/vacpp.jam

@@ -75,6 +75,22 @@ if [ os.name ] = AIX
     flags vacpp.compile C++FLAGS : -qfuncsect ;
     flags vacpp.link LINKFLAGS <link>static : -qtwolink ;
 
+
+    # The -bnoipath strips the prepending (relative) path of libraries from
+    # the loader section in the target library or executable. Hence, during
+    # load-time LIBPATH (identical to LD_LIBRARY_PATH) or a hard-coded
+    # -blibpath (*similar* to -lrpath/-lrpath-link) is searched. Without
+    # this option, the prepending (relative) path + library name is
+    # hard-coded in the loader section, causing *only* this path to be
+    # searched during load-time. Note that the AIX linker does not have an
+    # -soname equivalent, this is as close as it gets.
+    #
+    # The above options are definately for AIX 5.x, and most likely also for
+    # AIX 4.x and AIX 6.x. For details about the AIX linker see:
+    # http://download.boulder.ibm.com/ibmdl/pub/software/dw/aix/es-aix_ll.pdf
+    #
+    flags vacpp.link LINKFLAGS <link>shared : -bnoipath ;
+
     # Run-time linking
     flags vacpp.link EXE-LINKFLAGS <link>shared : -brtl -qtwolink ;
 }