misc/wasm, cmd/link: Go 1.17.2 causes WASM builds to throw `command line too long` with many environment variables [1.17 backport]

[gopherbot]

@dmitshur requested issue #49011 to be considered for backport to the next 1.17 minor release.

@gopherbot Please open backport tracking issues.

This is a follow-up to the security fix included in Go 1.17.2 and 1.16.9 for issue #48797; without it some programs are unable to run.

[gopherbot]

Change https://golang.org/cl/359399 mentions this issue: [release-branch.go1.17] cmd/link: increase reserved space for passing env on wasm

[gopherbot]

Closed by merging 18b9702 to release-branch.go1.17.