Merge pull request #2377 from Dicebot/fix-13210-makefile-dll

[reg] Fix 13210 : libphobos2.so not being built
Merge pull request #2376 from DmitryOlshansky/issue-12923

Fix issue 12923
Merge pull request #2384 from AndrewEdwards/2.066

Cherry-picking commits from master to 2.066 branch (for RC1)