Final libstdc++.so should not contain rpath to make libvtv usable.
It's up to final binaries to link against proper libvtv.

Bug: https://bugs.gentoo.org/582524
Bug: https://gcc.gnu.org/PR85884
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -217,7 +217,6 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
 
 # Symbol versioning for shared libraries.
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -511,7 +511,6 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
 
 @ENABLE_SYMVERS_TRUE@CLEANFILES = libstdc++-symbols.ver $(version_dep)
--- a/libstdc++-v3/src/c++11/Makefile.am
+++ b/libstdc++-v3/src/c++11/Makefile.am
@@ -204,5 +204,4 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX --tag disable-shared \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
--- a/libstdc++-v3/src/c++11/Makefile.in
+++ b/libstdc++-v3/src/c++11/Makefile.in
@@ -496,7 +496,6 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX --tag disable-shared \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
 
 all: all-am
--- a/libstdc++-v3/src/c++98/Makefile.am
+++ b/libstdc++-v3/src/c++98/Makefile.am
@@ -273,5 +273,4 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX --tag disable-shared \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
--- a/libstdc++-v3/src/c++98/Makefile.in
+++ b/libstdc++-v3/src/c++98/Makefile.in
@@ -500,7 +500,6 @@ CXXLINK = \
 	$(LIBTOOL) --tag CXX --tag disable-shared \
 	$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
 	--mode=link $(CXX) \
-	$(VTV_CXXLINKFLAGS) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
 
 all: all-am