build: Fix build errors with MSVC.

* gettext-tools/libgettextpo/exported.sh.in: Remove one level of eval.
* gettext-tools/libgettextpo/Makefile.am (config.h): Redirect compiler output to
stderr. Remove symbols that contain an '@'.
* libtextstyle/lib/Makefile.am (config.h): Likewise.

gettext-tools/libgettextpo/Makefile.am

@@ -175,8 +175,8 @@ config.h: $(BUILT_SOURCES)
 	          ;; \
 	      esac; \
 	    done; \
-	  } 5>&1 \
-	    | sed -e 's,.* ,,' | LC_ALL=C sort | LC_ALL=C uniq \
+	  } 5>&1 1>&2 \
+	    | sed -e 's,.* ,,' | grep -v '@' | LC_ALL=C sort | LC_ALL=C uniq \
 	    | sed -e 's,^obstack_free$$,__obstack_free,' \
 	    | sed -e 's,^\(.*\)$$,#define \1 libgettextpo_\1,' > config.h-t && \
 	  if test -f config.h; then \

gettext-tools/libgettextpo/exported.sh.in

@@ -1,6 +1,6 @@
 #! /bin/sh
 #
-# Copyright (C) 2006 Free Software Foundation, Inc.
+# Copyright (C) 2006, 2009, 2019 Free Software Foundation, Inc.
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -20,5 +20,4 @@
 # This is a separate script because $(GLOBAL_SYMBOL_PIPE) cannot be used in a
 # Makefile, since it may contain dollar signs.
 
-nm_cmd="@NM@ $1 | @GLOBAL_SYMBOL_PIPE@"
-eval $nm_cmd
+@NM@ "$1" | @GLOBAL_SYMBOL_PIPE@

libtextstyle/lib/Makefile.am

@@ -226,8 +226,8 @@ config.h: $(BUILT_SOURCES) libtextstyle.sym
 	            ;; \
 	        esac; \
 	      done; \
-	    } 5>&1 \
-	      | sed -e 's,.* ,,' | LC_ALL=C sort | LC_ALL=C uniq \
+	    } 5>&1 1>&2 \
+	      | sed -e 's,.* ,,' | grep -v '@' | LC_ALL=C sort | LC_ALL=C uniq \
 	      | LC_ALL=C join -v 1 - libtextstyle.sym \
 	      | sed -e 's,^\(.*\)$$,#define \1 libtextstyle_\1,' > config.h-t; \
 	  } 6>&1 && \