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

$ go version
go version go1.12 linux/amd64

Does this issue reproduce with the latest release?

Yes, with Go compiled from 45d74aa.

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

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/ayke/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/ayke"
GOPROXY=""
GORACE=""
GOROOT="/usr/local/go"
GOTMPDIR=""
GOTOOLDIR="/usr/local/go/pkg/tool/linux_amd64"
GCCGO="/usr/bin/gccgo"
CC="clang"
CXX="clang++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build818149774=/tmp/go-build -gno-record-gcc-switches"

Reproducing

I'm not exactly sure how to reproduce this yet, but this is the error I'm getting:

panic: overlapping edits: [52942,53034)->"func() { _cgo0 := /*line :1305:33*/b.C; _cgo1 := _Ctype_uint(line); _cgoCheckPointer(_cgo0); _cgoCheckPointer(_cgo1); _Cfunc_LLVMSetCurrentDebugLocation2(_cgo0, _cgo1); }()", [52996,53006)->" /*line :1305:56*/_Ctype_uint /*line :1305:66*/"

It is clearly related to CGo somehow and I think it may be caused by a signature mismatch. There are two symbols with the same name and a different signature. One lives in the Go package as a .cpp file, the other is declared in a header file (included by CGo) and lives in an archive file. My theory is that CGo picks the one at one time and a different one some other time which leads to a conflict.
That's a lot of guessing and little reproducing. But this is a large and complicated system and I'm not sure how to make it smaller, but perhaps you can see something that is wrong so I can look into it further?

Tested with two different system linkers: ld.bfd and ld.lld-8.

Sort-of related:
https://reviews.llvm.org/D60484
https://reviews.llvm.org/rL358086

Also: this is with Go modules disabled, if that is relevant.