cmd/internal/testdir: Test/fixedbugs/issue16037_run.go failures

[gopherbot]

#!watchflakes
default <- pkg == "cmd/internal/testdir" && test == "Test/fixedbugs/issue16037_run.go"

Issue created automatically to collect these failures.

Example (log):

=== RUN   Test/fixedbugs/issue16037_run.go
=== PAUSE Test/fixedbugs/issue16037_run.go
=== CONT  Test/fixedbugs/issue16037_run.go
    testdir_test.go:147: exit status 1
        2025/01/29 04:05:45 build failed: exit status 1
        # command-line-arguments
        <unknown line number>: internal compiler error: panic: runtime error: invalid memory address or nil pointer dereference
        
        goroutine 1 [running]:
        runtime/debug.Stack()
...
        	cmd/compile/internal/noder/unified.go:195 +0xbc
        cmd/compile/internal/noder.LoadPackage({0x1416118, 0x1, 0x1})
        	cmd/compile/internal/noder/noder.go:77 +0x438
        cmd/compile/internal/gc.Main(0xb66838)
        	cmd/compile/internal/gc/main.go:208 +0xe70
        main.main()
        	cmd/compile/main.go:57 +0x150
        
        
--- FAIL: Test/fixedbugs/issue16037_run.go (218.52s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "cmd/internal/testdir" && test == "Test/fixedbugs/issue16037_run.go"

2025-01-28 22:19 gotip-netbsd-arm go@7764c502 cmd/internal/testdir.Test/fixedbugs/issue16037_run.go (log)

=== RUN   Test/fixedbugs/issue16037_run.go
=== PAUSE Test/fixedbugs/issue16037_run.go
=== CONT  Test/fixedbugs/issue16037_run.go
    testdir_test.go:147: exit status 1
        2025/01/29 04:05:45 build failed: exit status 1
        # command-line-arguments
        <unknown line number>: internal compiler error: panic: runtime error: invalid memory address or nil pointer dereference
        
        goroutine 1 [running]:
        runtime/debug.Stack()
...
        	cmd/compile/internal/noder/unified.go:195 +0xbc
        cmd/compile/internal/noder.LoadPackage({0x1416118, 0x1, 0x1})
        	cmd/compile/internal/noder/noder.go:77 +0x438
        cmd/compile/internal/gc.Main(0xb66838)
        	cmd/compile/internal/gc/main.go:208 +0xe70
        main.main()
        	cmd/compile/main.go:57 +0x150
        
        
--- FAIL: Test/fixedbugs/issue16037_run.go (218.52s)

— watchflakes

[cherrymui]

Dup of #73820