Go patch committed: Better error for unexpected digit

[Ian Lance Taylor via Gcc-patches]

This patch to the Go frontend generates a better error for an
unexpected digit.  A digit character is not invalid in general, but
it's not permitted at the start of an identifier.  Report a better
error message.  The test case is issue11359.go in the source repo.
Bootstrapped and ran Go testsuite on x86_64-pc-linux-gnu.  Committed
to mainline.

Ian

68556694c83efd397b04dffa9248c9acc537ab97
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE
index 681debb0392..1bada25300d 100644
--- a/gcc/go/gofrontend/MERGE
+++ b/gcc/go/gofrontend/MERGE
@@ -1,4 +1,4 @@
-3e8f49a2137a87fdaba51c3002ddbe41ab18ed46
+8b913a1865e36d4bd105f29aa0b12264a4e03515
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
diff --git a/gcc/go/gofrontend/lex.cc b/gcc/go/gofrontend/lex.cc
index 156a90c7baf..e71b8cddf65 100644
--- a/gcc/go/gofrontend/lex.cc
+++ b/gcc/go/gofrontend/lex.cc
@@ -743,6 +743,13 @@ Lex::next_token()
                if (Lex::is_unicode_letter(ci))
                  return this->gather_identifier();
 
+               if (!issued_error && Lex::is_unicode_digit(ci))
+                 {
+                   go_error_at(this->location(),
+                               "identifier cannot begin with digit");
+                   issued_error = true;
+                 }
+
                if (!issued_error)
                  go_error_at(this->location(),
                              "invalid character 0x%x in input file",