Fix Issue 13212 - Windows line endings handled incorrectly by ddoc macros

Handle \r as \n in macro definitions to prevent a trailing carriage
return on a macro with an empty line following it.
Fix Issue 12745 - [Ddoc] Underscore is removed from numbers
Test 2 underscores
Add DirectX library path

64-bit only. If 32-bit COFF support is ever added we can add that to the `Environment32` section as well.

Fixes #13265
Fix Issue 8269 - The 'with statement' does not observe temporary object lifetime
Fix counting unittest indent with Windows line endings
Fix removing trailing whitespace in documented unittest (Windows)
Fix reading ddoc ESCAPES on Windows
Merge pull request #3855 from yebblies/issue8269

Issue 8269 - The 'with statement' does not observe temporary object lifetime
fix Issue 13204 - recursive alias declaration
fix Issue 2427 - Function call in struct initializer fails to compile
fix Issue 2438 - Cannot get types of delegate properties
fix Issue 4225 - forward reference of opCall (mangle.c:81: char* mangle(Declaration*): Assertion `fd && fd->inferRetType' failed.)
fix Issue 4423 - [tdpl] enums of struct types
fix Issue 6699 - More cases of __error in error messages
fix Issue 7477 - Enum structs without specified values
fix Issue 10629 - [ICE](dt.c 106) with void array
fix Issue 10928 - Fails to create closures that reference structs with dtor
fix Issue 13217 - nothrow, template function and delegate: compilation error
fix Issue 13187 - Function wrongly deduced as pure