LDC 1.18.0 发布，高性能 D 语言编译器

LDC 是一个高性能的 D 语言编译器，后端基于 LLVM 架构生成跨平台的二进制文件，生成的二进制执行程序性能强劲。

最近 LDC 社区的开发效率比较高，可以迅速的跟进 DMD 编译器的新特性和 BUG 修复，本身也有很好的跨平台支持特性，包含 WebAssembly / Android / FreeBSD on PowerPC 等平台。

版本重要特性：

1. D 语言版本支持升级到最新稳定版 2.088.1
2. 支持最新的 LLVM 9.0 架构
3. Preliminary Android CI, incl. experimental prebuilt armv7a package generation (API level 21, i.e., Android 5+). (#3164)
4. 升级内置的 dub 版本到 1.17.0+ （因为此版本改进了 dub 对 LDC 编译器的支持） (dlang/dub#1755, Wiki)
5. Init symbols of zero-initialized structs are no longer emitted. (#3131)
6. druntime: DMD-compatible {load,store}Unaligned and prefetch added to core.simd. (ldc-developers/druntime#163)
7. JIT improvements, incl. multi-threaded compilation. (#2758, #3154, #3174) 

支持的 LLVM 架构版本：

• Supports LLVM 3.9 - 9.0.

Bug 修复：

1. Don't error out when initializing a void vector. (#3130, #3139)
2. druntime: Fix exception chaining for latest MSVC runtime v14.23, shipping with Visual Studio 2019 v16.3. (ldc-developers/druntime#164)
3. Keep lvalue-ness when casting associative array to another AA. (#3162, #3179) (new)
4. druntime: Fix regression for POSIX systems without backtrace[_symbols], introduced in beta1. (#3165, dlang/druntime#2796)
5. Fix compilability regression with make, introduced in beta2. (#3188, #3191) (new)

其他问题处理：

1. Buggy older ld.bfd linker versions may wrongly strip out required symbols, e.g., ModuleInfos (so that e.g. no module ctors/dtors are run). LDC defaults to ld.gold on Linux.
2. LDC does not zero the padding area of a real variable. This may lead to wrong results if the padding area is also considered. See #770. Does not apply to real members inside structs etc.