add -Wl,-Bsymbolic to link c-archive in the same way as c-shared

Thank you @ianlancetaylor for the suggestion and insight!

This resolved the issue outlined in golang/go#30822.

Author: mewmew

a/Makefile

@@ -1,7 +1,7 @@
 all: a.so
 
 a.so: a.c go-a.a
-	clang -shared -o $@ $^ -lpthread
+	clang -Wl,-Bsymbolic -shared -o $@ $^ -lpthread
 
 go-a.a: go-a.go
 	CGO_ENABLED=1 go build -buildmode=c-archive -o $@ $<

b/Makefile

@@ -1,7 +1,7 @@
 all: b.so
 
 b.so: b.c go-b.a
-	clang -shared -o $@ $^ -lpthread
+	clang -Wl,-Bsymbolic -shared -o $@ $^ -lpthread
 
 go-b.a: go-b.go
 	CGO_ENABLED=1 go build -buildmode=c-archive -o $@ $<

c/Makefile

@@ -1,7 +1,7 @@
 all: c.so
 
 c.so: c.c go-c.a
-	clang -shared -o $@ $^ -lpthread
+	clang -Wl,-Bsymbolic -shared -o $@ $^ -lpthread
 
 go-c.a: go-c.go
 	CGO_ENABLED=1 go build -buildmode=c-archive -o $@ $<