gotest: explicitly skip type descriptors

Type descriptors are normally weak and nm will report them as V,
so we will skip them when collecting the list of symbols.
But when not using GNU nm, they may be reported as D,
so also skip them in symstogo.

This fixes go/doc/check on Solaris.

Change-Id: I32275129d485956fef704ca01c29b41793d00ae7
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/215900
Reviewed-by: Cherry Zhang <cherryyz@google.com>
diff --git a/libgo/testsuite/gotest b/libgo/testsuite/gotest
index de4a392..33f99d7 100755
--- a/libgo/testsuite/gotest
+++ b/libgo/testsuite/gotest
@@ -517,6 +517,11 @@
     if expr "$tp" : '^\.' >/dev/null 2>&1; then
       continue
     fi
+    # Skip type descriptors.  These are normally skipped because they
+    # are weak symbols, but if not using GNU nm we may see them here.
+    if expr "$tp" : '^type\.\.' >/dev/null 2>&1; then
+      continue
+    fi
     s=$(echo "$tp" | sed -e 's/\.\.z2f/%/g' | sed -e 's/.*%//')
     # Screen out methods (X.Y.Z).
     if ! expr "$s" : '^[^.]*\.[^.]*$' >/dev/null 2>&1; then