Attribute associated with incorrect decl

Attribute associated with incorrect declaration
```
[extern("C")]
time(t:^uint64):uint64
```

```
Vector.usyntax:940:7: error: cannot apply linkage specifier to a parameter
time(t:^uint64):uint64
```

The same error occurs for the following:
```
time(t:^uint64)<extern("C")>:uint64
```

```
time<extern("C")>(t:^uint64):uint64
```