Improve code gen for localgot
convert escape mask literal constant to ESCAPEmask
fix Issue 9726 - Add minimum % coverage required for -cov testing
Add assertion and fix AST identity that had broken by template instantiation
Fixes Issue 6089 - extern variable should not have an initializer.
Merge pull request #1759 from WalterBright/fix9726

fix Issue 9726 - Add minimum % coverage required for -cov testing
Merge pull request #1752 from WalterBright/improvelocalgot

Improve code gen for localgot
Merge pull request #1762 from AndrejMitrovic/Fix6089

Issue 6089 - extern variable should not have an initializer.
Merge pull request #1757 from braddr/backend-escape

convert escape mask literal constant to ESCAPEmask
Merge pull request #1760 from 9rnsr/fix_ast_identity

Add assertion and fix AST identity that had broken by template instantiation