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.
fix Issue 10334 - ddoc should prefer simple syntax for template instantiations with one parameter
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
Merge pull request #2173 from 9rnsr/fix10334

Issue 10334 - ddoc should prefer simple syntax for template instantiations with one parameter
Fix failing test-case diagnostic due to pulling #1353.
Merge pull request #2202 from AndrejMitrovic/Fixup1353

Fix failing test-case diagnostic due to pulling #1353.
Fixup #1353 test-case not using {RESULTS_DIR}.
Merge pull request #2203 from AndrejMitrovic/Fixup1353_2

Fixup #1353 test-case not using {RESULTS_DIR}.