cmd/compile: mark temps with new AutoTemp flag, and use it.

This is an extension of
https://go-review.googlesource.com/c/31662/
to mark all the temporaries, not just the ssa-generated ones.

Before-and-after ls -l `go tool -n compile` shows a 3%
reduction in size (or rather, a prior 3% inflation for
failing to filter temps out properly.)

Replaced name-dependent "is it a temp?" tests with calls to
*Node.IsAutoTmp(), which depends on AutoTemp.  Also replace
calls to istemp(n) with n.IsAutoTmp(), to reduce duplication
and clean up function name space.  Generated temporaries
now come with a "." prefix to avoid (apparently harmless)
clashes with legal Go variable names.

Fixes #17644.
Fixes #17240.

Change-Id: If1417f29c79a7275d7303ddf859b51472890fd43
Reviewed-on: https://go-review.googlesource.com/32255
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/test/uintptrescapes2.go b/test/uintptrescapes2.go
index d39bab764a..57c21edbce 100644
--- a/test/uintptrescapes2.go
+++ b/test/uintptrescapes2.go
@@ -22,10 +22,10 @@ func F2(a ...uintptr) {} // ERROR "escaping ...uintptr" "a does not escape"
 
 func G() {
 	var t int                       // ERROR "moved to heap"
-	F1(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to F1: autotmp" "&t escapes to heap"
+	F1(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to F1: .?autotmp" "&t escapes to heap"
 }
 
 func H() {
 	var v int                                // ERROR "moved to heap"
-	F2(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to newobject: autotmp" "live at call to F2: autotmp" "escapes to heap"
+	F2(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to newobject: .?autotmp" "live at call to F2: .?autotmp" "escapes to heap"
 }