Release 0.7.0

Version 0.7.0 has many smaller improvements that you can see below. Some of the highlights include initial support for tinygo test, support for garbage collection in most targets including WebAssembly, and the addition of the HiFive1 rev B board, which is based on the new RISC-V architecture.

0.7.0

• command line
  • try more locations to find Clang built-in headers
  • add support for tinygo test
  • build current directory if no package is specified
  • support custom .json target spec with -target flag
  • use zversion.go to detect version of GOROOT version
  • make initial heap size configurable for some targets (currently WebAssembly
    only)
• cgo
  • add support for bitfields using generated getters and setters
  • add support for anonymous structs
• compiler
  • show an error instead of panicking on duplicate function definitions
  • allow packages like github.com/tinygo-org/tinygo/src/* by aliasing it
  • remove //go:volatile support
    It has been replaced with the runtime/volatile package.
  • allow poiners in map keys
  • support non-constant syscall numbers
  • implement non-blocking selects
  • add support for the -tags flag
  • add support for string to []rune conversion
  • implement a portable conservative garbage collector (with support for wasm)
  • add the //go:noinline pragma
• standard library
  • os: add os.Exit and syscall.Exit
  • os: add several stubs
  • runtime: fix heap corruption in conservative GC
  • runtime: add support for math intrinsics where supported, massively
    speeding up some benchmarks
  • testing: add basic support for testing
• targets
  • add support for a generic target that calls __tinygo_* functions for
    peripheral access
  • arduino-nano33: add support for this board
  • hifive1: add support for this RISC-V board
  • reelboard: add e-paper pins
  • reelboard: add PowerSupplyActive to enable voltage for on-board devices
  • wasm: put the stack at the start of linear memory, to detect stack
    overflows