add same-line docs to aggregate types & templates

[WebFreak001]

Now code like class X {} /// foo properly gets documentation, like in the dmd -D output.

Extends #438

This code in D-Scanner now properly gets recognized as documented:

class C{} /// a
interface I{} /// b
enum e = 0; /// c
void f(){} /// d
struct S{} /// e
template T(){} /// f
union U{} /// g

This will fully fix https://github.com/dlang-community/D-Scanner/issues/499

[codecov[bot]]

Codecov Report

Merging #455 (1d3cbd7) into master (beadf0b) will increase coverage by 0.01%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #455      +/-   ##
==========================================
+ Coverage   82.83%   82.84%   +0.01%     
==========================================
  Files          11       11              
  Lines        8306     8311       +5     
==========================================
+ Hits         6880     6885       +5     
  Misses       1426     1426              

Impacted Files	Coverage Δ
src/dparse/parser.d	91.29% <100.00%> (+0.01%)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update beadf0b...1d3cbd7. Read the comment docs.