[cleanup] Indentation fix.
[cleanup] Merge common code in IrTypeStruct::get() and IrTypeClass::addBaseClassData()
Fix issue with multiple initializers for classes that implement interfaces.

This could happen when having e.g. a ClassReferenceExp in
addition to the default initializer. Unfortunately, I could
not easily distill a test case for this issue from a large
application I was working on.
Fix issue 726: Wrong alignment for struct fields on x86_64/amd64
Merge pull request #741 from AlexeyProkhin/issue726

Fix Issue #726 — Wrong alignment for struct fields on x86_64/amd64
Merge pull request #742 from klickverbot/vtbl-initializer

Fix issue with multiple initializers for classes that implement interfaces.
Win64: do not prepend extra underscore when mangling symbol names in inline assembly
Merge pull request #744 from kinke/asm

Win64: do not prepend extra underscore when mangling symbol names in inline assembly
Fix generation of DWARF debug information in LLVM 3.6.

The creation of complex expressions (e.g. address calculations) was extended in LLVM 3.6.
Merge pull request #735 from redstar/llvm36

Try to fix LLVM 3.6 build.
Small druntime changes.

- Create template for strtold() on Win64 (issue #728)
- Fix an assembler warning on Linux/PPC64le
Added test cases for GitHub issues #662 and #739.