libgo/testsuite: ignore symbols with a leading dot in symtogo

On AIX, a function has two symbols, a text symbol (with a leading dot)
    and a data one (without it).
    As the tests must be run only once, only the data symbol can be used to
    retrieve the final go symbol. Therefore, all symbols beginning with a dot
    are ignored by symtogo.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/177837

From-SVN: r272666

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-1d6578a20a9a2ee599a07f03cf7f8e7797d72b9c
+d3d0f3c5bbe9d272178d55bdb907b07c188800e1
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/testsuite/gotest

@@ -501,6 +501,13 @@ localname() {
 symtogo() {
   result=""
   for tp in $*; do
+    # Discard symbols with a leading dot.
+    # On AIX, this will remove function text symbols (with a leading dot).
+    # Therefore, only function descriptor symbols (without this leading dot)
+    # will be used to retrieve the go symbols, avoiding duplication.
+    if expr "$tp" : '^\.' >/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