cmd/go: pass -Wl,-z,nodelete for c-shared mode with gccgo

This is the gccgo version of CL 15605.

For https://gcc.gnu.org/PR114699

For #11100
For #12582
For #12873

Change-Id: I30e23130737022d772971f0bd629b57269174886
Reviewed-on: https://go-review.googlesource.com/c/go/+/582975
Reviewed-by: Than McIntosh <[email protected]>
Commit-Queue: Ian Lance Taylor <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>

Author: ianlancetaylor

src/cmd/go/internal/work/gccgo.go

@@ -484,6 +484,9 @@ func (tools gccgoToolchain) link(b *Builder, root *Action, out, importcfg string
 
 	case "c-shared":
 		ldflags = append(ldflags, "-shared", "-nostdlib")
+		if cfg.Goos != "windows" {
+			ldflags = append(ldflags, "-Wl,-z,nodelete")
+		}
 		ldflags = append(ldflags, goLibBegin...)
 		ldflags = append(ldflags, "-lgo", "-lgcc_s", "-lgcc", "-lc", "-lgcc")