[Perf] [metal] Support TLS and SIMD group reduction for range-for kernels#1358

Merged

k-ye merged 3 commits intotaichi-dev:masterfrom k-ye:tls

Jul 1, 2020

+193-27

Commits on Jun 29, 2020

Commits on Jun 30, 2020

[skip ci] enforce code format
taichi-gardener
committed