add explanation for Pull 2164
encapsulate instance lookup
fix Issue 10382 - ICE when catching illegal type
C-style variadic functions with C++ linkage use the C calling convention.
Issue 10389 - Infinite recursion on printing self-referential StructLiteralExp.
Update library return types to match druntime.
Merge pull request #2183 from klickverbot/structliteralexp-tochars

Avoid infinite recursion on StructLiteralExp::toChars().
Use isWindows to determine correct system linkage.
Merge pull request #2195 from ibuclaw/gencfunc

Update library return types to match druntime.
Merge pull request #2197 from ibuclaw/linkage

Use isWindows to determine correct system linkage.
Merge pull request #2193 from yebblies/varlinkage

[DDMD] C-style variadic functions with C++ linkage use the C calling convention
Merge pull request #2188 from WalterBright/refactor_instances

Refactor instances
Merge pull request #2190 from 9rnsr/fix10382

[REG2.059] Issue 10382 - ICE when catching illegal type