scons: We have C++ in several libraries, so always link with the C++ compiler

Prevents missing symbols in libGL.so when LLVM is disabled.

scons/gallium.py

@@ -551,6 +551,10 @@ def generate(env):
     env.Append(LINKFLAGS = linkflags)
     env.Append(SHLINKFLAGS = shlinkflags)
 
+    # We have C++ in several libraries, so always link with the C++ compiler
+    if env['gcc']:
+        env['LINK'] = env['CXX']
+
     # Default libs
     env.Append(LIBS = [])
 

scons/llvm.py

@@ -147,8 +147,6 @@ def generate(env):
         except OSError:
             print 'scons: llvm-config version %s failed' % llvm_version
             return
-        else:
-            env['LINK'] = env['CXX']
 
     assert llvm_version is not None
     env['llvm'] = True