Added 'ansic' os support for minimal (embedded) targets (#13088)

* os:any implementation
* os:asny: omit flock/funlock calls in echoBinSafe
* Disabled default "unhandled expection" reporting for `--os:any` to reduce
code size. Added unhandledExceptionHook instead which can be used to get
a notification from Nim and handle it from the application.

compiler/platform.nim

@@ -22,7 +22,7 @@ type
     osNone, osDos, osWindows, osOs2, osLinux, osMorphos, osSkyos, osSolaris,
     osIrix, osNetbsd, osFreebsd, osOpenbsd, osDragonfly, osAix, osPalmos, osQnx,
     osAmiga, osAtari, osNetware, osMacos, osMacosx, osIos, osHaiku, osAndroid, osVxWorks
-    osGenode, osJS, osNimVM, osStandalone, osNintendoSwitch
+    osGenode, osJS, osNimVM, osStandalone, osNintendoSwitch, osAny
 
 type
   TInfoOSProp* = enum
@@ -177,6 +177,10 @@ const
       objExt: ".o", newLine: "\x0A", pathSep: ":", dirSep: "/",
       scriptExt: ".sh", curDir: ".", exeExt: ".elf", extSep: ".",
       props: {ospNeedsPIC, ospPosix}),
+     (name: "Any", parDir: "..", dllFrmt: "lib$1.so", altDirSep: "/",
+      objExt: ".o", newLine: "\x0A", pathSep: ":", dirSep: "/",
+      scriptExt: ".sh", curDir: ".", exeExt: "", extSep: ".",
+      props: {}),
      ]
 
 type