cmd/go: OOB panic in cmd/go/internal/list.runList

#!watchflakes
default <- pkg == "golang.org/x/tools/gopls/internal/cache" && test == "TestMatchingPortsStdlib"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestMatchingPortsStdlib
    port_test.go:43: err: exit status 2: stderr: panic: runtime error: index out of range [0] with length 0
        
        goroutine 1 [running]:
        cmd/go/internal/list.runList({0x7ff704ffbd80, 0x7ff7050c0600}, 0xb93ce242990?, {0xb93ce13c1c0, 0x2, 0x4})
        	cmd/go/internal/list/list.go:887 +0x30cd
        main.invoke(0x7ff7050698c8, {0xb93ce13c110, 0xd, 0xf})
        	cmd/go/main.go:340 +0x8bf
        main.main()
        	cmd/go/main.go:219 +0xee5
        
--- FAIL: TestMatchingPortsStdlib (44.89s)

— watchflakes