fix Issue 10431 - ICE(DMD 2.063) in struct.c:741 (1)
Fix issue 10388 - Compile DMD with Clang on Mac OS X.
fix issue 9247 - Compiler accepts opaque struct returned by value from
function pointer declaration.
Add Port::fequal for longdouble comparisons.
fix Issue 10726 - Bogus Circular Reference error if opEquals defined and has a loop

This is also the better fix for issue 10567.
Update 10567 test case for exhaustive check of TypeInfo generation
Merge pull request #2458 from hpohl/9247

fix issue 9247 - Compiler accepts opaque struct returned by value from function pointer declaration.
fix issue 10788 - forward reference of enum member E from another module
fix issue 10787 - static ~this attributes position
Merge pull request #2461 from ibuclaw/fequal

Add Port::fequal for longdouble comparisons.
fix Issue 4481 - ICE(glue.c,!vthis->csym) or compiles, depending on the import statements order
fix issue 10792 - Bad diagnostic on new eponymous enum template syntax
Merge pull request #2465 from hpohl/10792

fix issue 10792 - Bad diagnostic on new eponymous enum template syntax
Merge pull request #2463 from 9rnsr/fix4481

Issue 4481 - ICE(glue.c,!vthis->csym) or compiles, depending on the import statements order
Merge pull request #2462 from hpohl/10788

[REG??] fix issue 10788 - forward reference of enum member E from another module
Merge pull request #2460 from hpohl/10787

fix issue 10787 - static ~this attributes position
Merge pull request #2454 from jacob-carlborg/clang

Fix issue 10388 - Compile DMD with Clang on Mac OS X.
Merge pull request #2452 from 9rnsr/fix10431

Issue 10431 - ICE(DMD 2.063) in struct.c:741 (1)
Merge pull request #2421 from 9rnsr/fix10726

[REG2.064a] Issue 10726 - Bogus Circular Reference error if opEquals defined and has a loop