For now, accept lost result due to missing flow to variable capture

The result listed here is valid but we don't find it because we still have
a jump step from the definition of an `SsaVariable` to the
`SsaCaptureVariable`, rather than from the last use before the capture.

See for example `reqContent` on line 543 of go/ql/test/library-tests/semmle/go/frameworks/Twirp/rpc/notes/service.twirp.go . there is a use on line 544, which taints it, and a capture variable on line 574, but the jump step goes from 543 to 574, skipping 544.

Author: owen-mc

go/ql/test/library-tests/semmle/go/frameworks/Twirp/RequestForgery.expected

@@ -1,46 +1,15 @@
 #select
-| server/main.go:30:38:30:48 | selection of Text | rpc/notes/service.twirp.go:538:25:538:32 | selection of Body | server/main.go:30:38:30:48 | selection of Text | The $@ of this request depends on a $@. | server/main.go:30:38:30:48 | selection of Text | URL | rpc/notes/service.twirp.go:538:25:538:32 | selection of Body | user-provided value |
 | server/main.go:30:38:30:48 | selection of Text | server/main.go:19:56:19:61 | definition of params | server/main.go:30:38:30:48 | selection of Text | The $@ of this request depends on a $@. | server/main.go:30:38:30:48 | selection of Text | URL | server/main.go:19:56:19:61 | definition of params | user-provided value |
 edges
 | client/main.go:16:35:16:78 | &... | server/main.go:19:56:19:61 | definition of params | provenance |  |
-| rpc/notes/service.twirp.go:473:6:473:13 | definition of typedReq | rpc/notes/service.twirp.go:477:44:477:51 | typedReq | provenance |  |
-| rpc/notes/service.twirp.go:477:44:477:51 | typedReq | server/main.go:19:56:19:61 | definition of params | provenance |  |
-| rpc/notes/service.twirp.go:493:2:496:2 | capture variable reqContent | rpc/notes/service.twirp.go:495:35:495:44 | reqContent | provenance |  |
-| rpc/notes/service.twirp.go:495:35:495:44 | reqContent | server/main.go:19:56:19:61 | definition of params | provenance |  |
-| rpc/notes/service.twirp.go:538:2:538:33 | ... := ...[0] | rpc/notes/service.twirp.go:544:27:544:29 | buf | provenance |  |
-| rpc/notes/service.twirp.go:538:25:538:32 | selection of Body | rpc/notes/service.twirp.go:538:2:538:33 | ... := ...[0] | provenance | Src:MaD:1 MaD:3 |
-| rpc/notes/service.twirp.go:543:2:543:11 | definition of reqContent | rpc/notes/service.twirp.go:574:2:577:2 | capture variable reqContent | provenance |  |
-| rpc/notes/service.twirp.go:544:27:544:29 | buf | rpc/notes/service.twirp.go:543:2:543:11 | definition of reqContent | provenance | MaD:2 |
-| rpc/notes/service.twirp.go:554:6:554:13 | definition of typedReq | rpc/notes/service.twirp.go:558:44:558:51 | typedReq | provenance |  |
-| rpc/notes/service.twirp.go:558:44:558:51 | typedReq | server/main.go:19:56:19:61 | definition of params | provenance |  |
-| rpc/notes/service.twirp.go:574:2:577:2 | capture variable reqContent | rpc/notes/service.twirp.go:576:35:576:44 | reqContent | provenance |  |
-| rpc/notes/service.twirp.go:576:35:576:44 | reqContent | server/main.go:19:56:19:61 | definition of params | provenance |  |
+| client/main.go:16:35:16:78 | &... [postupdate] | client/main.go:16:35:16:78 | &... | provenance |  |
 | server/main.go:19:56:19:61 | definition of params | server/main.go:19:56:19:61 | definition of params [Return] | provenance |  |
 | server/main.go:19:56:19:61 | definition of params | server/main.go:30:38:30:48 | selection of Text | provenance |  |
 | server/main.go:19:56:19:61 | definition of params | server/main.go:30:38:30:48 | selection of Text | provenance |  |
-| server/main.go:19:56:19:61 | definition of params [Return] | client/main.go:16:35:16:78 | &... | provenance |  |
-| server/main.go:19:56:19:61 | definition of params [Return] | rpc/notes/service.twirp.go:473:6:473:13 | definition of typedReq | provenance |  |
-| server/main.go:19:56:19:61 | definition of params [Return] | rpc/notes/service.twirp.go:493:2:496:2 | capture variable reqContent | provenance |  |
-| server/main.go:19:56:19:61 | definition of params [Return] | rpc/notes/service.twirp.go:554:6:554:13 | definition of typedReq | provenance |  |
-| server/main.go:19:56:19:61 | definition of params [Return] | rpc/notes/service.twirp.go:574:2:577:2 | capture variable reqContent | provenance |  |
-models
-| 1 | Source: net/http; Request; true; Body; ; ; ; remote; manual |
-| 2 | Summary: google.golang.org/protobuf/proto; ; false; Unmarshal; ; ; Argument[0]; Argument[1]; taint; manual |
-| 3 | Summary: io; ; false; ReadAll; ; ; Argument[0]; ReturnValue[0]; taint; manual |
+| server/main.go:19:56:19:61 | definition of params [Return] | client/main.go:16:35:16:78 | &... [postupdate] | provenance |  |
 nodes
 | client/main.go:16:35:16:78 | &... | semmle.label | &... |
-| rpc/notes/service.twirp.go:473:6:473:13 | definition of typedReq | semmle.label | definition of typedReq |
-| rpc/notes/service.twirp.go:477:44:477:51 | typedReq | semmle.label | typedReq |
-| rpc/notes/service.twirp.go:493:2:496:2 | capture variable reqContent | semmle.label | capture variable reqContent |
-| rpc/notes/service.twirp.go:495:35:495:44 | reqContent | semmle.label | reqContent |
-| rpc/notes/service.twirp.go:538:2:538:33 | ... := ...[0] | semmle.label | ... := ...[0] |
-| rpc/notes/service.twirp.go:538:25:538:32 | selection of Body | semmle.label | selection of Body |
-| rpc/notes/service.twirp.go:543:2:543:11 | definition of reqContent | semmle.label | definition of reqContent |
-| rpc/notes/service.twirp.go:544:27:544:29 | buf | semmle.label | buf |
-| rpc/notes/service.twirp.go:554:6:554:13 | definition of typedReq | semmle.label | definition of typedReq |
-| rpc/notes/service.twirp.go:558:44:558:51 | typedReq | semmle.label | typedReq |
-| rpc/notes/service.twirp.go:574:2:577:2 | capture variable reqContent | semmle.label | capture variable reqContent |
-| rpc/notes/service.twirp.go:576:35:576:44 | reqContent | semmle.label | reqContent |
+| client/main.go:16:35:16:78 | &... [postupdate] | semmle.label | &... [postupdate] |
 | server/main.go:19:56:19:61 | definition of params | semmle.label | definition of params |
 | server/main.go:19:56:19:61 | definition of params | semmle.label | definition of params |
 | server/main.go:19:56:19:61 | definition of params [Return] | semmle.label | definition of params [Return] |