drop legacy Go support

[mythi]

Go 1.9 was released in August 2017 so it's safe to make a claim that projects are already using new enough Go version.

Tested with:

$ go version
go version go1.13.8 linux/amd64
$ GO111MODULE=off ./test.sh
ok      github.com/modern-go/reflect2-tests     0.005s  coverage: 12.3% of statements in github.com/modern-go/reflect2
ok      github.com/modern-go/reflect2-tests/test15      0.004s  coverage: 6.4% of statements in github.com/modern-go/reflect2
ok      github.com/modern-go/reflect2-tests/tests       0.010s  coverage: 65.4% of statements in github.com/modern-go/reflect2

Signed-off-by: Mikko Ylinen mikko.ylinen@intel.com

[codecov-io]

Codecov Report

Merging #11 (bb009fe) into master (7e6ae53) will increase coverage by 4.86%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master      #11      +/-   ##
==========================================
+ Coverage   60.42%   65.29%   +4.86%     
==========================================
  Files          20       19       -1     
  Lines         753      533     -220     
==========================================
- Hits          455      348     -107     
+ Misses        282      172     -110     
+ Partials       16       13       -3     

Impacted Files	Coverage Δ
go_above_19.go	100.00% <ø> (ø)
reflect2.go	64.04% <100.00%> (+0.23%)	:arrow_up:
type_map.go	91.30% <100.00%> (+43.84%)	:arrow_up:
safe_struct.go	20.00% <0.00%> (-1.43%)	:arrow_down:
unsafe_ptr.go	13.33% <0.00%> (-0.96%)	:arrow_down:
unsafe_slice.go	80.72% <0.00%> (-0.41%)	:arrow_down:
unsafe_link.go	100.00% <0.00%> (ø)
unsafe_iface.go	0.00% <0.00%> (ø)
... and 12 more

---

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[mythi]

any comments?

[mythi]

rebased to resolve conflicts, force pushed.