Normalize backend's elf structures with system headers.
Forward to system headers when available.
implement UDA for module declaration
fix Issue 13356 - [ICE] (dmd 2.066: statement.c:754) with recursive Algebraic
[Refactoring] Remove goto jumps
fix Issue 11888 - Incorrect behaviour taking slice from return value
fix Issue 13563 - ICE with opIndexAssign op-overloading and ModuleScopeOperator
fix Issue 13564 - nested struct destructor trying to access members of a global class fail to compile
fix Issue 12979 - Nothrow violation error is hidden by inline assembler

- deprecate using unattributed asm in attributed functions

- add explicit attributes on asm statments (unverified by compiler)

  asm pure nothrow @nogc @trusted {
    //...
  }

- added new CompoundAsmStatement because the parser
  already splits asm blocks into many AsmStatements
Merge pull request #3947 from IgorStepanov/module-attributes

[enh] implement UDA for module declaration
Remove internals for typedef declaration
Deprecate is(T == typedef) syntax
fix Issue 12985 - Better error message for not supported array operation
Replace "did you forget a [] ?" with "possible missing []"
Merge pull request #4039 from 9rnsr/fix12985

Issue 12985 - Better error message for not supported array operation
Merge pull request #4038 from 9rnsr/remove_typedef

Remove internals for typedef declaration
[Refactoring] Reorder function declarations
Check redundant/conflicting attributes more
Check invalid syntax and redundancy on static constructors

Improve diagnostic for issue 6677.
Set prefix attributes in storage_class of (Unittest|New|Delete)Declaration

Partially fix issue 8081.
Merge pull request #4040 from 9rnsr/fix13564

[REG2.065] Issue 13564 - nested struct destructor trying to access members of a global class fail to compile