cmd/cgo: error message for an unexpected type does not include the line number

[bruceesmith]

Please answer these questions before submitting your issue. Thanks!

What version of Go are you using (go version)? 1.11.1

Does this issue reproduce with the latest release? Yes

What operating system and processor architecture are you using (go env)? linux/amd64

What did you do? In the linked file on play.golang.org, put the commented C code into ld.h, then run "go build" against the ld.go program

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best. ---> https://play.golang.org/p/Ey5ZbkqleNU

What did you expect to see?

Go 1.10 and earlier build the program without errors

What did you see instead?

bruce@calochilus:/tmp$ go build ld.go

command-line-arguments

-: unexpected: 16-byte float type - long double
bruce@calochilus:/tmp$

NOTE: if the "union {" line in ld.h and the matching "} value;" line are commented out, then "go build" succeeds.

[ianlancetaylor]

Standalone test case:

package main

/*
typedef long double             SmiFloat128;

typedef struct SV {
    union {
        SmiFloat128         float128;
    } value;
} SV;
*/
import "C"

type ts struct {
	tv *C.SV
}

func main() {}

[gopherbot]

Change https://golang.org/cl/152158 mentions this issue: cmd/cgo: use a plausible position for typedef error messages