runtime: simplify stack traces

Make the stack traces more readable for new
Go programmers while preserving their utility for old hands.

- Change status number [4] to string.
- Elide frames in runtime package (internal details).
- Swap file:line and arguments.
- Drop 'created by' for main goroutine.
- Show goroutines in order of allocation:
  implies main goroutine first if nothing else.

There is no option to get the extra frames back.
Uncomment 'return 1' at the bottom of symtab.c.

$ 6.out
throw: all goroutines are asleep - deadlock!

goroutine 1 [chan send]:
main.main()
       /Users/rsc/g/go/src/pkg/runtime/x.go:22 +0x8a

goroutine 2 [select (no cases)]:
main.sel()
       /Users/rsc/g/go/src/pkg/runtime/x.go:11 +0x18
created by main.main
       /Users/rsc/g/go/src/pkg/runtime/x.go:19 +0x23

goroutine 3 [chan receive]:
main.recv(0xf8400010a0, 0x0)
       /Users/rsc/g/go/src/pkg/runtime/x.go:15 +0x2e
created by main.main
       /Users/rsc/g/go/src/pkg/runtime/x.go:20 +0x50

goroutine 4 [chan receive (nil chan)]:
main.recv(0x0, 0x0)
       /Users/rsc/g/go/src/pkg/runtime/x.go:15 +0x2e
created by main.main
       /Users/rsc/g/go/src/pkg/runtime/x.go:21 +0x66
$

$ 6.out index
panic: runtime error: index out of range

goroutine 1 [running]:
main.main()
        /Users/rsc/g/go/src/pkg/runtime/x.go:25 +0xb9
$

$ 6.out nil
panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x22ca]

goroutine 1 [running]:
main.main()
        /Users/rsc/g/go/src/pkg/runtime/x.go:28 +0x211
$

$ 6.out panic
panic: panic

goroutine 1 [running]:
main.main()
        /Users/rsc/g/go/src/pkg/runtime/x.go:30 +0x101
$

R=golang-dev, qyzhai, n13m3y3r, r
CC=golang-dev
http://codereview.appspot.com/4907048

1 files changed, 0 insertions, 8 deletions

diff --git a/test/golden.out b/test/golden.out
index 655ceda56..d2a104b79 100644
--- a/test/golden.out
+++ b/test/golden.out
@@ -4,19 +4,15 @@
 =========== ./cmp2.go
 panic: runtime error: comparing uncomparable type []int
 
-
 =========== ./cmp3.go
 panic: runtime error: comparing uncomparable type []int
 
-
 =========== ./cmp4.go
 panic: runtime error: hash of unhashable type []int
 
-
 =========== ./cmp5.go
 panic: runtime error: hash of unhashable type []int
 
-
 =========== ./deferprint.go
 printing: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
 42 true false true +1.500000e+000 world 0x0 [0/0]0x0 0x0 0x0 255
@@ -115,11 +111,9 @@ PASS
 =========== interface/fail.go
 panic: interface conversion: *main.S is not main.I: missing method Foo
 
-
 =========== interface/returntype.go
 panic: interface conversion: *main.S is not main.I2: missing method Name
 
-
 == nilptr/
 
 == syntax/
@@ -154,12 +148,10 @@ M
 =========== fixedbugs/bug113.go
 panic: interface conversion: interface is int, not int32
 
-
 =========== fixedbugs/bug148.go
 2 3
 panic: interface conversion: interface is main.T, not main.T
 
-
 =========== fixedbugs/bug328.go
 0x0