cmd/cgo: use -Wl,--no-gc-sections if available

This change adds `--no-gc-sections` to the external linker if the flag
is understood.

zig cc passes `--gc-sections` to the underlying linker, which then
causes undefined symbol errors when compiling with cgo but without C
code. Minimal example:

**main.go**
```
package main
import _ "runtime/cgo"
func main() {}
```

Run (works after the patch, doesn't work before):

```
CGO_ENABLED=1 CC="zig cc" go build main.go
```

@ianlancetaylor suggested:

> It would be fine with me if somebody wants to send a cgo patch that
passes -Wl,--no-gc-sections, with a fallback if that option is not
supported.

... and this is what we are doing. Tested with zig
0.10.0-dev.896+e620b692c

Fixes #52690

Author: motiejus

src/cmd/go/internal/work/exec.go

@@ -2528,6 +2528,13 @@ func (b *Builder) compilerCmd(compiler []string, incdir, workdir string) []strin
 		a = append(a, "-Qunused-arguments")
 	}
 
+	// zig cc passes --gc-sections to the underlying linker, which then causes
+	// undefined symbol errors when compiling with cgo but without C code.
+	// https://github.com/golang/go/issues/52690
+	if b.gccSupportsFlag(compiler, "-Wl,--no-gc-sections") {
+		a = append(a, "-Wl,--no-gc-sections")
+	}
+
 	// disable word wrapping in error messages
 	a = append(a, "-fmessage-length=0")