cmd/compile,runtime: `index out of range` panic in `cmd/internal/src.PosTable.Pos`

[gopherbot]

#!watchflakes
post <- log ~ `runtime error: index out of range` && log ~ `^\s*cmd/internal/src\.\(\*PosTable\)\.Pos`

Issue created automatically to collect these failures.

Example (log):

../../../../../pkg/mod/google.golang.org/appengine@v1.6.7/internal/datastore/datastore_v3.pb.go:3149:2: internal compiler error: '(*PutResponse).XXX_Unmarshal': panic during early deadcode while compiling (*PutResponse).XXX_Unmarshal:

runtime error: index out of range [134217730] with length 219

goroutine 337 [running]:
cmd/compile/internal/ssa.Compile.func1()
	cmd/compile/internal/ssa/compile.go:49 +0x7c
panic({0x9be900?, 0xc003371f20?})
	runtime/panic.go:770 +0x154
cmd/internal/src.(*PosTable).Pos(...)
...
cmd/compile/internal/ssagen.buildssa(0xc0015d0000, 0x3)
	cmd/compile/internal/ssagen/ssa.go:575 +0x20d4
cmd/compile/internal/ssagen.Compile(0xc0015d0000, 0x3)
	cmd/compile/internal/ssagen/pgen.go:216 +0x48
cmd/compile/internal/gc.compileFunctions.func5.1(0x0?)
	cmd/compile/internal/gc/compile.go:182 +0x4c
cmd/compile/internal/gc.compileFunctions.func3.1()
	cmd/compile/internal/gc/compile.go:164 +0x48
created by cmd/compile/internal/gc.compileFunctions.func3 in goroutine 20
	cmd/compile/internal/gc/compile.go:163 +0x214

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "google.golang.org/appengine/internal/datastore" && test == ""

2023-11-14 16:31 linux-ppc64-sid-buildlet telemetry@69313e64 go@ddb38c3f google.golang.org/appengine/internal/datastore [build] (log)

../../../../../pkg/mod/google.golang.org/appengine@v1.6.7/internal/datastore/datastore_v3.pb.go:3149:2: internal compiler error: '(*PutResponse).XXX_Unmarshal': panic during early deadcode while compiling (*PutResponse).XXX_Unmarshal:

runtime error: index out of range [134217730] with length 219

goroutine 337 [running]:
cmd/compile/internal/ssa.Compile.func1()
	cmd/compile/internal/ssa/compile.go:49 +0x7c
panic({0x9be900?, 0xc003371f20?})
	runtime/panic.go:770 +0x154
cmd/internal/src.(*PosTable).Pos(...)
...
cmd/compile/internal/ssagen.buildssa(0xc0015d0000, 0x3)
	cmd/compile/internal/ssagen/ssa.go:575 +0x20d4
cmd/compile/internal/ssagen.Compile(0xc0015d0000, 0x3)
	cmd/compile/internal/ssagen/pgen.go:216 +0x48
cmd/compile/internal/gc.compileFunctions.func5.1(0x0?)
	cmd/compile/internal/gc/compile.go:182 +0x4c
cmd/compile/internal/gc.compileFunctions.func3.1()
	cmd/compile/internal/gc/compile.go:164 +0x48
created by cmd/compile/internal/gc.compileFunctions.func3 in goroutine 20
	cmd/compile/internal/gc/compile.go:163 +0x214

— watchflakes

[mknyszek]

Duplicate of #64290.