Move RPATH flags to AIX per-compiler information files

Move RPATH flags out of Platform/AIX.cmake into platform-specific
compiler information files Platform/AIX-XL and Platform/AIX-GNU.
The flags need to be set for each compiler of each language.

Modules/Platform/AIX-GNU.cmake

@@ -19,5 +19,7 @@ endif()
 set(__AIX_COMPILER_GNU 1)
 
 macro(__aix_compiler_gnu lang)
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG "-Wl,-blibpath:")
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG_SEP ":")
   set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "${CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS} -Wl,-G")
 endmacro()

Modules/Platform/AIX-XL.cmake

@@ -19,6 +19,8 @@ endif()
 set(__AIX_COMPILER_XL 1)
 
 macro(__aix_compiler_xl lang)
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG "-Wl,-blibpath:")
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG_SEP ":")
   set(CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS "-G -Wl,-brtl,-bnoipath")  # -shared
   set(CMAKE_SHARED_LIBRARY_LINK_${lang}_FLAGS "-Wl,-brtl,-bnoipath,-bexpall")  # +s, flag for exe link to use shared lib
   set(CMAKE_SHARED_LIBRARY_${lang}_FLAGS " ")

Modules/Platform/AIX.cmake

@@ -9,8 +9,6 @@ SET(CMAKE_DL_LIBS "-lld")
 # When our own RPATH is to be added it may be inserted before the
 # "always" paths.
 SET(CMAKE_PLATFORM_REQUIRED_RUNTIME_PATH /usr/lib /lib)
-SET(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-blibpath:")
-SET(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG_SEP ":")
 
 # Files named "libfoo.a" may actually be shared libraries.
 SET_PROPERTY(GLOBAL PROPERTY TARGET_ARCHIVES_MAY_BE_SHARED_LIBS 1)