Improve cross-compilation support (replace `version` checks by BuildPlatform runtime checks) ...

Also fixes #1249. For LDC as implicit cross compiler, the file
extensions for libraries and object files etc. don't depend on the
compiler, but solely on the target. Targets selected with `--arch` are
correctly probed by dub, so that the parsed `BuildPlatform` represents
the target platform.

ldc2: Only use `-L--no-as-needed` for Linux *targets*

ldc2: Fix MSVC target detection for static libs ...

With --arch, the build (target) platform might now diverge from the host
platform. The compiler's default triple doesn't matter when
cross-compiling, so use the <name>.lib MSVC format when targeting Windows
but not MinGW.

This fixes one aspect of #1599.

Enable specifying full target triples as --arch for ldc2 ...

By treating all 'architectures' containing a `-` as `-mtriple` values.
E.g., `dub --arch=wasm32-unknown-unknown-wasm` to cross-compile to
WebAssembly. This dub switch is already used when probing the compiler,
so the build platform detection works as expected.

Also add `wasm` as detected platform and use the .wasm executable file
extension (for ldc2).

This fixes #1749 when moving the `-mtriple` option from the dub config
file to the dub command line.

Support separate linking with ldc2 ...

This is basically #1548 with an augmented set of compiler flags being
included in the linking command lines.

Restrict extra ldc2 invocation for static libs to Windows hosts ...

Don't perform the does-default-target-triple-contain-msvc check on
non-Windows hosts (which would need a hacked LLVM to return true on
other hosts).

Support a few more ldc2 command-line options

fix #1003 - Check empty ldflags

Use -dumpfullversion to determine GDC version

Perform the tool chain checks based on the compiler name. ...

Gets rid of the additional methods in the Compiler interface and moves the checks to a more central location, since other generators apart from BuildGenerator might want to perform the checks in the future. Also keeps the API "package" for now to avoid adding insufficiently though-out public APIs.

Change toolchainRequirements fields to Dependency. ...

Also removes some API clutter from Compiler and PackageRecipe.

toolchainRequirements recipe support

Merge pull request #1560 from dlang/cache_ldc_coff_status ...

Cache the COFF generation status for LDC.

Merge pull request #1542 from ohdatboi/implement_1427 ...

Add betterC build option

Merge pull request #1543 from ohdatboi/fix_1228 ...

Fix dynamicLibrary extensions on OSX. Fixes #1228

Cache the COFF generation status for LDC. ...

This can speed up the up-to-date check considerably when using LDC2 on Windows.

Fix detection for other msvc triples ...

e.g. x86-pc-win32-msvc

Add betterC build option

Fix dynamicLibrary extensions on OSX. Fixes #1228

Rename Path to NativePath. ...

Matches the changes done in vibe.d 0.8.x and vibe-core.

Refactor determinePlatform, determineArchitecture, and determineCompiler from dub.platform into strings that can be pasted into generatePlatformProbeFile and remove unused imports.

unused imports

make pic inherited for dynamic libraries

remove defaultlib for ldc shared libs

ldc: call probePlatform as other Compilers do.

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

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.

Remove deprecated functionality to prepare for 1.0.0.