ci: Add job with -fsanitize-memory-param-retval

Author: real-or-random

.github/workflows/ci.yml

@@ -485,18 +485,24 @@ jobs:
       matrix:
         configuration:
           - env_vars:
+              CTIMETESTS: 'yes'
               CFLAGS: '-fsanitize=memory -fsanitize-recover=memory -g'
           - env_vars:
               ECMULTGENKB: 2
               ECMULTWINDOW: 2
+              CTIMETESTS: 'yes'
               CFLAGS: '-fsanitize=memory -fsanitize-recover=memory -g -O3'
+          - env_vars:
+              # -fsanitize-memory-param-retval is clang's default, but our build system disables it
+              # when ctime_tests when enabled.
+              CFLAGS: '-fsanitize=memory -fsanitize-recover=memory -fsanitize-memory-param-retval -g'
+              CTIMETESTS: 'no'
 
     env:
       ECDH: 'yes'
       RECOVERY: 'yes'
       SCHNORRSIG: 'yes'
       ELLSWIFT: 'yes'
-      CTIMETESTS: 'yes'
       CC: 'clang'
       SECP256K1_TEST_ITERS: 32
       ASM: 'no'