Fixes Issue 8787 - Better diagnostic on non-final interface function with a body.
fix Issue 9278 - ICE todt.c:692 when float containing struct is defined after use
fix Issue 9293 - enum struct with StructInitializer reports weird error

`VarDeclaration::getConstInitializer` should return an actual expression, even if init is not an `ExpInitializer`.
Fixes Issue 8742 - ICE on anon class derived from nested class.
start on improving auto layout
reformat
improve stack layout
Use VERSION file to generate version string
no optimizations for iasm
Merge pull request #1468 from WalterBright/b4

Improve stack layout to use less space and improve performance
simplify interface to back end
remove debug printf
fix license
Merge pull request #1471 from WalterBright/b5

simplify interface to back end
Merge pull request #1469 from 9rnsr/vergen

Use VERSION file to generate version string
add version.c to manifest
Merge pull request #1472 from WalterBright/b6

Add vergen.c to win32.mak
Add vergen.c to posix.mak
Merge pull request #1473 from 9rnsr/b6

Add vergen.c into posix.mak
fix Issue 9309 - Regression (2.061): -O -release generates wrong code

In current, all nested functions should be weak purity at most.