Copy check_names.py and friends from development

Copy the following files:
    tests/scripts/check_names.py
    tests/scripts/list_internal_identifiers.py
    tests/scripts/list-identifiers.sh

Copy the version from b19be6b5f3c9a92b5b17fa27e16901f132f1a310, which is the
result of merging https://github.com/ARMmbed/mbedtls/pull/1638 into the
development branch.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/scripts/list-identifiers.sh b/tests/scripts/list-identifiers.sh
index a1c3d2d..9b93080 100755
--- a/tests/scripts/list-identifiers.sh
+++ b/tests/scripts/list-identifiers.sh
@@ -1,8 +1,11 @@
 #!/bin/bash
 #
 # Create a file named identifiers containing identifiers from internal header
-# files or all header files, based on --internal flag.
+# files, based on the --internal flag.
 # Outputs the line count of the file to stdout.
+# A very thin wrapper around list_internal_identifiers.py for backwards
+# compatibility.
+# Must be run from Mbed TLS root.
 #
 # Usage: list-identifiers.sh [ -i | --internal ]
 #
@@ -24,7 +27,7 @@
 set -eu
 
 if [ -d include/mbedtls ]; then :; else
-    echo "$0: must be run from root" >&2
+    echo "$0: Must be run from Mbed TLS root" >&2
     exit 1
 fi
 
@@ -47,32 +50,17 @@
 
 if [ $INTERNAL ]
 then
-    HEADERS=$( ls include/mbedtls/*_internal.h library/*.h | egrep -v 'compat-1\.3\.h|bn_mul' )
+    tests/scripts/list_internal_identifiers.py
+    wc -l identifiers
 else
-    HEADERS=$( ls include/mbedtls/*.h include/psa/*.h library/*.h | egrep -v 'compat-1\.3\.h|bn_mul' )
-    HEADERS="$HEADERS 3rdparty/everest/include/everest/everest.h 3rdparty/everest/include/everest/x25519.h"
+    cat <<EOF
+Sorry, this script has to be called with --internal.
+
+This script exists solely for backwards compatibility with the previous
+iteration of list-identifiers.sh, of which only the --internal option remains in
+use. It is a thin wrapper around list_internal_identifiers.py.
+
+check-names.sh, which used to depend on this script, has been replaced with
+check_names.py and is now self-complete.
+EOF
 fi
-
-rm -f identifiers
-
-grep '^[^ /#{]' $HEADERS | \
-    sed -e 's/^[^:]*://' | \
-    egrep -v '^(extern "C"|(typedef )?(struct|union|enum)( {)?$|};?$)' \
-    > _decls
-
-if true; then
-sed -n -e 's/.* \**\([a-zA-Z_][a-zA-Z0-9_]*\)(.*/\1/p' \
-       -e 's/.*(\*\(.*\))(.*/\1/p' _decls
-grep -v '(' _decls | sed -e 's/\([a-zA-Z0-9_]*\)[;[].*/\1/' -e 's/.* \**//'
-fi > _identifiers
-
-if [ $( wc -l < _identifiers ) -eq $( wc -l < _decls ) ]; then
-    rm _decls
-    egrep -v '^(u?int(16|32|64)_t)$' _identifiers | sort > identifiers
-    rm _identifiers
-else
-    echo "$0: oops, lost some identifiers" 2>&1
-    exit 1
-fi
-
-wc -l identifiers