cmd/compile/internal/pgo: remove node weights from IRNode

Actual PGO operation doesn't use these weights at all. They are
theoretically used when printing a dot graph for debugging, but that
doesn't actually work because these weights are always zero.

These fields are initialized by looking for a NodeMap entry with key
{CallerName: sym, CalleeName: "", CallSiteOffset: 0}. These entries will
never exist, as we never put entries in NodeMap without CalleeName.

Since they aren't really used and don't work, just remove them entirely,
which offers nice simplification.

This leaves IRNode with just a single field. I keep the type around as a
future CL will make the *ir.Func optional, allowing nodes with a name
but no IR.

Change-Id: I1646654cad1d0779ce071042768ffad2a7e6ff49
Reviewed-on: https://go-review.googlesource.com/c/go/+/494616
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Michael Pratt <mpratt@google.com>

0 files changed, 0 insertions, 0 deletions