Revert "cmd/compile: de-virtualize interface calls"

This reverts commit 4e0c7c3f61475116c4ae8d11ef796819d9c404f0.

Reason for revert: The presence-of-optimization test program is fragile, breaks under noopt, and might break if the Go libraries are tweaked.  It needs to be (re)written without reference to other packages.

Change-Id: I3aaf1ab006a1a255f961a978e9c984341740e3c7
Reviewed-on: https://go-review.googlesource.com/38097
Reviewed-by: Keith Randall <khr@golang.org>

1 files changed, 0 insertions, 64 deletions

diff --git a/test/devirt.go b/test/devirt.go
deleted file mode 100644
index a2211f185c..0000000000
--- a/test/devirt.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// errorcheck -0 -d=ssa/opt/debug=3
-
-package main
-
-import (
-	"crypto/sha1"
-	"errors"
-	"fmt"
-	"sync"
-)
-
-func f0() {
-	v := errors.New("error string")
-	_ = v.Error() // ERROR "de-virtualizing call$"
-}
-
-func f1() {
-	h := sha1.New()
-	buf := make([]byte, 4)
-	h.Write(buf)   // ERROR "de-virtualizing call$"
-	_ = h.Sum(nil) // ERROR "de-virtualizing call$"
-}
-
-func f2() {
-	// trickier case: make sure we see this is *sync.rlocker
-	// instead of *sync.RWMutex,
-	// even though they are the same pointers
-	var m sync.RWMutex
-	r := m.RLocker()
-
-	// deadlock if the type of 'r' is improperly interpreted
-	// as *sync.RWMutex
-	r.Lock() // ERROR "de-virtualizing call$"
-	m.RLock()
-	r.Unlock() // ERROR "de-virtualizing call$"
-	m.RUnlock()
-}
-
-type multiword struct{ a, b, c int }
-
-func (m multiword) Error() string { return fmt.Sprintf("%d, %d, %d", m.a, m.b, m.c) }
-
-func f3() {
-	// can't de-virtualize this one yet;
-	// it passes through a call to iconvT2I
-	var err error
-	err = multiword{1, 2, 3}
-	if err.Error() != "1, 2, 3" {
-		panic("bad call")
-	}
-
-	// ... but we can do this one
-	err = &multiword{1, 2, 3}
-	if err.Error() != "1, 2, 3" { // ERROR "de-virtualizing call$"
-		panic("bad call")
-	}
-}
-
-func main() {
-	f0()
-	f1()
-	f2()
-	f3()
-}