[cleanup] fix indent style
Improve COMPILE_SEPARATELY to supply optional compiler switches when link .o files
Improve error propagation from function body semantic.
Change inNonRoot function to Dsymbol class member
fix Issue 11931 - Linkers "Symbol Undefined" again with dmd HEAD when -g specified

Also add test case for issue 7595.
Remove some dead files
Remove Expression::dump and replace usages with Expression::print
Rename toString to toStringExp to avoid conflict with D's toString
Merge pull request #3115 from yebblies/toStringExp

[DDMD] Rename toString to toStringExp to avoid conflict with D's toString
Merge pull request #3114 from yebblies/dump

[cleanup] Remove Expression::dump and replace usages with Expression::print
Merge pull request #3113 from yebblies/cleanup

[cleanup] Remove some dead files
And visitor for Initializer and Expression
Move inlineCost and inlineCost3 to a visitor class
Merge pull request #3110 from yebblies/inlinecost

[refactor] Move inlineCost and inlineCost3 to a visitor class
Cast visitor to void*
Merge pull request #3119 from yebblies/castvoid

[DDMD] Cast visitor to void*
Merge pull request #3107 from 9rnsr/fix11931

[REG2.065a] Issue 11931 - Linkers "Symbol Undefined" again with dmd HEAD when -g specified