go: carry stdlib cgo link inputs into GoLink (#4657)

**What type of PR is this?**
Bug fix

**What does this PR do? Why is it needed?**
runtime/cgo records CGO_LDFLAGS from the configuration used to build
GoStdLib in package metadata. go_stdlib_transition intentionally filters
irrelevant build tags and disables coverage, so a later GoLink action
may run in a different configuration.

When a C++ toolchain's linker flags refer to generated runtime files,
the recorded flags point to the stdlib configuration's files. GoLink
only declared its own configuration's C++ toolchain files, so sandboxed
links failed with an undeclared input.

Store the stdlib configuration's cgo link inputs on GoStdLib and add
them to GoLink. This keeps the transition's stdlib sharing behavior
while declaring the files whose paths may be replayed.

Add an analysis test with a generated C++ runtime archive and a build
tag filtered by go_stdlib_transition. The test fails before this change
because GoLink sees only one configured archive, and passes when both
inputs are declared.


**Which issues(s) does this PR fix?**

Fixes #

**Other notes for review**