msvcp120: Added std::ios_base::operator bool() implementation.

dlls/msvcp120/msvcp120.spec

@@ -913,9 +913,9 @@
 @ cdecl -arch=arm ??Bid@locale@std@@QAAIXZ(ptr) locale_id_operator_size_t
 @ thiscall -arch=i386 ??Bid@locale@std@@QAEIXZ(ptr) locale_id_operator_size_t
 @ cdecl -arch=win64 ??Bid@locale@std@@QEAA_KXZ(ptr) locale_id_operator_size_t
-@ stub -arch=arm ??Bios_base@std@@QBA_NXZ
-@ stub -arch=win32 ??Bios_base@std@@QBE_NXZ
-@ stub -arch=win64 ??Bios_base@std@@QEBA_NXZ
+@ cdecl -arch=arm ??Bios_base@std@@QBA_NXZ(ptr) ios_base_operator_bool
+@ thiscall -arch=i386 ??Bios_base@std@@QBE_NXZ(ptr) ios_base_operator_bool
+@ cdecl -arch=win64 ??Bios_base@std@@QEBA_NXZ(ptr) ios_base_operator_bool
 @ extern ??_7?$basic_ios@DU?$char_traits@D@std@@@std@@6B@ MSVCP_basic_ios_char_vtable
 @ extern ??_7?$basic_ios@GU?$char_traits@G@std@@@std@@6B@ MSVCP_basic_ios_short_vtable
 @ extern ??_7?$basic_ios@_WU?$char_traits@_W@std@@@std@@6B@ MSVCP_basic_ios_wchar_vtable

dlls/msvcp90/ios.c

@@ -5042,6 +5042,16 @@ void* __thiscall ios_base_op_fail(const ios_base *this)
     return ios_base_fail(this) ? NULL : (void*)this;
 }
 
+/* ??Bios_base@std@@QBA_NXZ */
+/* ??Bios_base@std@@QBE_NXZ */
+/* ??Bios_base@std@@QEBA_NXZ */
+DEFINE_THISCALL_WRAPPER(ios_base_operator_bool, 4)
+MSVCP_bool __thiscall ios_base_operator_bool(const ios_base *this)
+{
+    TRACE("(%p)\n", this);
+    return (this->state & (IOSTATE_failbit|IOSTATE_badbit)) == 0;
+}
+
 /* ?_Addstd@ios_base@std@@SAXPAV12@@Z */
 /* ?_Addstd@ios_base@std@@SAXPEAV12@@Z */
 void CDECL ios_base_Addstd(ios_base *add)