[gcc r11-4801] libstdc++: Fix symbol version conflict in linker script

[Jonathan Wakely]

https://gcc.gnu.org/g:887515acd27e49c176395ab76d5826959d89cb9b

commit r11-4801-g887515acd27e49c176395ab76d5826959d89cb9b
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Nov 6 19:53:36 2020 +0000

    libstdc++: Fix symbol version conflict in linker script
    
    The change in r11-4748-50b840ac5e1d6534e345c3fee9a97ae45ced6bc7 causes
    a build error on Solaris, due to the new explicit instantiation matching
    patterns for two different symbol versions.
    
    libstdc++-v3/ChangeLog:
    
            * config/abi/pre/gnu.ver (GLIBCXX_3.4.21): Tighten up patterns
            for basic_stringbuf that refer to __xfer_bufptrs.

Diff:
---
 libstdc++-v3/config/abi/pre/gnu.ver | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/config/abi/pre/gnu.ver b/libstdc++-v3/config/abi/pre/gnu.ver
index ed68ffa2872..2d0f87aa7cc 100644
--- a/libstdc++-v3/config/abi/pre/gnu.ver
+++ b/libstdc++-v3/config/abi/pre/gnu.ver
@@ -1774,7 +1774,8 @@ GLIBCXX_3.4.21 {
     _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]ERKNS_12basic_stringI[cw]S2_S3_EESt13_Ios_Openmode;
     _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]ESt13_Ios_Openmode;
     _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EED[012]Ev;
-    _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]*__xfer_bufptrs*;
+    _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]EOS4_ONS4_14__xfer_bufptrsE;
+    _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]14__xfer_bufptrs[CD][12]*;
     _ZNSt7__cxx1115basic_stringbufI[cw]St11char_traitsI[cw]ESaI[cw]EE[a1346789]*;
 #   _ZNSt7__cxx1118basic_stringstreamI[cw]St11char_traitsI[cw]*;
     _ZNSt7__cxx1118basic_stringstreamI[cw]St11char_traitsI[cw]ESaI[cw]EEC[12]EOS4_;