Add inversesqrt to shader language.

servers/visual/shader_language.cpp

@@ -1377,6 +1377,10 @@ const ShaderLanguage::BuiltinFuncDef ShaderLanguage::builtin_func_defs[] = {
 	{ "sqrt", TYPE_VEC2, { TYPE_VEC2, TYPE_VOID } },
 	{ "sqrt", TYPE_VEC3, { TYPE_VEC3, TYPE_VOID } },
 	{ "sqrt", TYPE_VEC4, { TYPE_VEC4, TYPE_VOID } },
+	{ "inversesqrt", TYPE_FLOAT, { TYPE_FLOAT, TYPE_VOID } },
+	{ "inversesqrt", TYPE_VEC2, { TYPE_VEC2, TYPE_VOID } },
+	{ "inversesqrt", TYPE_VEC3, { TYPE_VEC3, TYPE_VOID } },
+	{ "inversesqrt", TYPE_VEC4, { TYPE_VEC4, TYPE_VOID } },
 	//builtins - common
 	{ "abs", TYPE_FLOAT, { TYPE_FLOAT, TYPE_VOID } },
 	{ "abs", TYPE_VEC2, { TYPE_VEC2, TYPE_VOID } },