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/live_syscall.go b/test/live_syscall.go
index 8aaa691187..f693e9357a 100644
--- a/test/live_syscall.go
+++ b/test/live_syscall.go
@@ -19,10 +19,10 @@ func f(uintptr) // ERROR "f assuming arg#1 is unsafe uintptr"
 
 func g() {
 	var t int
-	f(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to f: autotmp" "g &t does not escape"
+	f(uintptr(unsafe.Pointer(&t))) // ERROR "live at call to f: .?autotmp" "g &t does not escape"
 }
 
 func h() {
 	var v int
-	syscall.Syscall(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to Syscall: autotmp" "h &v does not escape"
+	syscall.Syscall(0, 1, uintptr(unsafe.Pointer(&v)), 2) // ERROR "live at call to Syscall: .?autotmp" "h &v does not escape"
 }