Temporary fix for 'Failed to apply the selected architecture x86_mscoff. Got ["x86"]' when passing --arch=x86_mscoff

Merge branch 'stable'

introduce x86-mscoff arch

Fix deprecation warning on Windows.

remove defaultlib for ldc shared libs

prepend defaultlib on dmd

ldc: call probePlatform as other Compilers do.

dmd, gdc: move common platform detection code to the base interface.

fix ldc optimization settings ...

Update ldc optimization flags to match ldmd behavior.

Just ran into a giant performance issue while benchmarking Mir? Took me an hour chatting w/ @9il to find this.

Fix -defaultlib flag for ldc2 compiler

Eliminate use of Json.opDispatch. ...

(cherry picked from commit bf65c40)

Align LDC invoke function on DMD one. Fix both #859 and #834.

Merge pull request #688 from dlang/fix_issue_618 ...

Fix library extensions for LDC when using the MS linker. Fixes #618.

Fix handling "libs" on Windows for BuildMode.allAtOnce. ...

Libs were mapped to sourceFiles and then ignored. Now they get correctly mapped to dflags.

Remove deprecated functionality to prepare for 1.0.0.

Determine linker used by LDC on Windows dynamically. Fixes #618.

Move getTargetFileName to Compiler interface. ...

See #618.

Fix build error on Windows.

Deprecate dub.compilers.compiler.defaultCompiler and improve docs. ...

Merges the code from compiler.defaultCompiler into the Dub class.

Improves documentation comment for Dub.defaultCompiler.

Move compiler registration code from to dub.dub. ...

Breaks the import cycle between dub.compilers.compiler and dub.compilers.ldc/gdc/dmd.

Move the isLinkerFile unit test to the function definition.

Fix warnings.

Mention version of removal for all deprecated public symbols.

Add documentation for dub.compilers.compiler/utils.

Move utility functions from dub.compilers.compiler to dub.compilers.utils.

Fix naming convention for the compiler handler classes and add documentation.

Move BuildPlatform to dub.platform and improve docs.

Fix all deprecation warnings on 2.071.0-b1, except for std.stream. ...

std.stream is still needed to support UTF filenames.

Quick fix to allow building shared libraries with LDC on Windows, with LDC on OS X, and with DMD on OS X.

Fix for issue #782. Analyze the output of pkg-config --libs <lib> and massage them if they appear to already be ready for direct use with the compiler. ...

This change allows using pkg-config within dub with .pc files that were written for use with the compiler directly, which can prove troublesome in some cases (for instance, when using the GtkD debian packages as mentioned in issue #7
82).
Basically, we analyze the output of pkg-config and fix up arguments so that they are suitable for the D compiler invokations through dub.

Arguments handled include:
- double "-L" flags (from gtkd3.pc for example) -> passed as single "-L" flags
- "-defaultlib" flags (from phobos2.pc for example) -> passed as-is (previous dub code used to pass them as "-Ldefaultlib")
- "-pthread" flags (from libavcode.pc for example) -> passed as "-L-l-pthread" (previous dub code used to pass them as-is)

The test case tests for these arguments explicitly, is currently only applicable to DMD frontend versions >= 2.068 as other frontends/versions seems to have some issues with shared libraries.