Martin Storsjö f95bd18b5f Revert "[Attr] support btf_type_tag attribute"
This reverts commits 737e4216c537c33aab8ec51880f06b8a54325b94 and
ce7ac9e66aba2b937b3d3b5505ce6cc75dcc56ac.

After those commits, the compiler can crash with a reduced
testcase like this:

$ cat reduced.c
void a(*);
void a() {}
$ clang -c reduced.c -O2 -g
2021-11-05 10:36:40 +02:00
..