BuildSystem: Add banan-os cmake platform

toolchain/cmake-platform/banan-os-GNU.cmake

@@ -0,0 +1,20 @@
+# This module is shared by multiple languages; use include blocker.
+include_guard()
+
+macro(__banan_os_compiler_gnu lang)
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG "-Wl,-rpath,")
+  set(CMAKE_SHARED_LIBRARY_RUNTIME_${lang}_FLAG_SEP ":")
+  set(CMAKE_SHARED_LIBRARY_RPATH_LINK_${lang}_FLAG "-Wl,-rpath-link,")
+  set(CMAKE_SHARED_LIBRARY_SONAME_${lang}_FLAG "-Wl,-soname,")
+  set(CMAKE_EXE_EXPORTS_${lang}_FLAG "-Wl,--export-dynamic")
+
+  # Initialize link type selection flags.  These flags are used when
+  # building a shared library, shared module, or executable that links
+  # to other libraries to select whether to use the static or shared
+  # versions of the libraries.
+  foreach(type SHARED_LIBRARY SHARED_MODULE EXE)
+    set(CMAKE_${type}_LINK_STATIC_${lang}_FLAGS "-Wl,-Bstatic")
+    set(CMAKE_${type}_LINK_DYNAMIC_${lang}_FLAGS "-Wl,-Bdynamic")
+  endforeach()
+
+endmacro()