Go patch committed: List indirect imports separately in export data

[Ian Lance Taylor <iant at golang dot org>]

Previously when the Go frontend generated export data that referred to
a type that was not defined in a directly imported package, it would
write the package name as additional information in the type's export
data.  That approach required all type information to be read in
order.  This patch changes the compiler to find all references to
indirectly imported packages, and write them out as an indirectimport
line in the import data.  This will permit the compiler to read
exported type data out of order.

The type traversal used to find indirect imports is a little more
complicated than necessary in preparation for later work.

Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
to mainline.

Ian

Attachment: patch.txt
Description: Text document