[dev.typeparams] cmd/compile: simplify ~r/~b naming

The compiler renames anonymous and blank result parameters to ~rN or
~bN, but the current semantics for computing N are rather annoying and
difficult to reproduce cleanly. They also lead to difficult to read
escape analysis results in tests.

This CL changes N to always be calculated as the parameter's index
within the function's result parameter tuple. E.g., if a function has
a single result, it will now always be named "~r0".

The normative change to this CL is fairly simple, but it requires
updating a lot of test expectations.

Change-Id: I58a3c94de00cb822cb94efe52d115531193c993c
Reviewed-on: https://go-review.googlesource.com/c/go/+/323010
Trust: Matthew Dempsky <mdempsky@google.com>
Trust: Dan Scales <danscales@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dan Scales <danscales@google.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/test/escape5.go b/test/escape5.go
index 82be2c38e7..73acfb46a9 100644
--- a/test/escape5.go
+++ b/test/escape5.go
@@ -22,19 +22,19 @@ func leaktoret(p *int) *int { // ERROR "leaking param: p to result"
 	return p
 }
 
-func leaktoret2(p *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: p to result ~r2"
+func leaktoret2(p *int) (*int, *int) { // ERROR "leaking param: p to result ~r0" "leaking param: p to result ~r1"
 	return p, p
 }
 
-func leaktoret22(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r2" "leaking param: q to result ~r3"
+func leaktoret22(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r0" "leaking param: q to result ~r1"
 	return p, q
 }
 
-func leaktoret22b(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r3" "leaking param: q to result ~r2"
+func leaktoret22b(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: q to result ~r0"
 	return leaktoret22(q, p)
 }
 
-func leaktoret22c(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r3" "leaking param: q to result ~r2"
+func leaktoret22c(p, q *int) (*int, *int) { // ERROR "leaking param: p to result ~r1" "leaking param: q to result ~r0"
 	r, s := leaktoret22(q, p)
 	return r, s
 }