…tion to

the nogo rule that enabled it to build itself without depending on itself.

Unfortunately that PR had to be rolled back because of complexities around
host configuration. Host configuration is terminal (specifically user defined
transitions are skipped) and therefore the transition in the nogo rule that
avoids dependency cycles was skipped. This prevented all host mode tools from
building.

This PR works around host mode limitations via using a config_setting with a
default value of noop nogo. [Making host mode buildable - although without nogo].
This config_setting is controlled via 2 boolean settings - 1 indicating that
we are currently bootstrapping nogo (and therefore cannot depend on it) and
another indicating that we are requesting the nogo binary thru go_context_data rule
to execute a build. This allows target, exec and other non-hostmode configs
to use nogo (as long as we're not bootstrapping nogo).

This PR replaces go_tool_librarys in org_golang_x_tools with aliases to the
go_default_library. go_tool_library cannot be removed 100% because it is used
by other parts of go_rules (eg: coverdata) to avoid circular deps.

…tion to

the nogo rule that enabled it to build itself without depending on itself.

Unfortunately that PR had to be rolled back because of complexities around
host configuration. Host configuration is terminal (specifically user defined
transitions are skipped) and therefore the transition in the nogo rule that
avoids dependency cycles was skipped. This prevented all host mode tools from
building.

This PR works around host mode limitations via using a config_setting with a
default value of noop nogo. [Making host mode buildable - although without nogo].
This config_setting is controlled via 2 boolean settings - 1 indicating that
we are currently bootstrapping nogo (and therefore cannot depend on it) and
another indicating that we are requesting the nogo binary thru go_context_data rule
to execute a build. This allows target, exec and other non-hostmode configs
to use nogo (as long as we're not bootstrapping nogo).

This PR replaces go_tool_librarys in org_golang_x_tools with aliases to the
go_default_library. go_tool_library cannot be removed 100% because it is used
by other parts of go_rules (eg: coverdata) to avoid circular deps.

…es_go into nogo_master_shim