* add `@bswap` builtin function. See #767
* comptime evaluation facilities are improved to be able to
handle a `@ptrCast` with a backing array.
* `@truncate` allows "truncating" a u0 value to any integer
type, and the result is always comptime known to be `0`.
* when specifying pointer alignment in a type expression,
the alignment value of pointers which do not have addresses
at runtime is ignored, and always has the default/ABI alignment
* threw in a fix to freebsd/x86_64.zig to update syntax from
language changes
* some improvements are pending #863closes#638closes#1733
std lib API changes
* io.InStream().readIntNe renamed to readIntNative
* io.InStream().readIntLe renamed to readIntLittle
* io.InStream().readIntBe renamed to readIntBig
* introduced io.InStream().readIntForeign
* io.InStream().readInt has parameter order changed
* io.InStream().readVarInt has parameter order changed
* io.InStream().writeIntNe renamed to writeIntNative
* introduced io.InStream().writeIntForeign
* io.InStream().writeIntLe renamed to writeIntLittle
* io.InStream().writeIntBe renamed to writeIntBig
* io.InStream().writeInt has parameter order changed
* mem.readInt has different parameters and semantics
* introduced mem.readIntNative
* introduced mem.readIntForeign
* mem.readIntBE renamed to mem.readIntBig and different API
* mem.readIntLE renamed to mem.readIntLittle and different API
* introduced mem.readIntSliceNative
* introduced mem.readIntSliceForeign
* introduced mem.readIntSliceLittle
* introduced mem.readIntSliceBig
* introduced mem.readIntSlice
* mem.writeInt has different parameters and semantics
* introduced mem.writeIntNative
* introduced mem.writeIntForeign
* mem.writeIntBE renamed to mem.readIntBig and different semantics
* mem.writeIntLE renamed to mem.readIntLittle and different semantics
* introduced mem.writeIntSliceForeign
* introduced mem.writeIntSliceNative
* introduced mem.writeIntSliceBig
* introduced mem.writeIntSliceLittle
* introduced mem.writeIntSlice
* removed mem.endianSwapIfLe
* removed mem.endianSwapIfBe
* removed mem.endianSwapIf
* added mem.littleToNative
* added mem.bigToNative
* added mem.toNative
* added mem.nativeTo
* added mem.nativeToLittle
* added mem.nativeToBig
closes#1414
std.io.InStream.read now can return less than buffer size
introduce std.io.InStream.readFull for previous behavior
add std.os.File.openWriteNoClobberC
rename std.os.deleteFileWindows to std.os.deleteFileW
remove std.os.deleteFilePosix
add std.os.deleteFileC
std.os.copyFile no longer takes an allocator
std.os.copyFileMode no longer takes an allocator
std.os.AtomicFile no longer takes an allocator
add std.os.renameW
add windows support for std.os.renameC
add a test for std.os.AtomicFile
