ntdll: Add stub for __chkstk on ARM.

dlls/kernel32/kernel32.spec

@@ -1629,7 +1629,7 @@
 @ stdcall WriteTapemark(ptr long long long)
 @ stdcall ZombifyActCtx(ptr)
 @ stdcall -arch=x86_64 -private __C_specific_handler(ptr long ptr ptr) ntdll.__C_specific_handler
-@ stdcall -arch=x86_64 -private -norelay __chkstk() ntdll.__chkstk
+@ stdcall -arch=arm,x86_64 -private -norelay __chkstk() ntdll.__chkstk
 @ stub _DebugOut
 @ stub _DebugPrintf
 @ stdcall _hread(long ptr long)

dlls/ntdll/ntdll.spec

@@ -1271,7 +1271,7 @@
 @ cdecl -private -arch=i386 _CIsin() NTDLL__CIsin
 @ cdecl -private -arch=i386 _CIsqrt() NTDLL__CIsqrt
 @ stdcall -arch=x86_64 __C_specific_handler(ptr long ptr ptr)
-@ stdcall -private -arch=x86_64 -norelay __chkstk()
+@ stdcall -private -arch=arm,x86_64 -norelay __chkstk()
 @ cdecl -private __isascii(long) NTDLL___isascii
 @ cdecl -private __iscsym(long) NTDLL___iscsym
 @ cdecl -private __iscsymf(long) NTDLL___iscsymf

dlls/ntdll/signal_arm.c

@@ -247,6 +247,12 @@ static inline void restore_fpu( CONTEXT *context, const ucontext_t *sigcontext )
     FIXME("not implemented\n");
 }
 
+/**************************************************************************
+ *		__chkstk (NTDLL.@)
+ *
+ * Should check if we can decrement SP by the value provided in r4, but we shouldn't need that.
+ */
+__ASM_GLOBAL_FUNC( __chkstk, "bx lr" )
 
 /***********************************************************************
  *		RtlCaptureContext (NTDLL.@)