Go patch committed: Check for notinheap struct at each struct field

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

This patch to the Go frontend checks for a notinheap struct at each
struct field.  When generating write barriers, we were only checking
for a notinheap struct at the outermost struct.  That mishandled the
case of setting a pointer to a notinheap struct as a field of another
struct that not notinheap.  This caused an invalid write barrier error
when building the 1.13 version of the runtime.  Bootstrapped and ran
Go testsuite on x86_64-pc-linux-gnu.  Committed to mainline.

Ian

Attachment: patch.txt
Description: Text document