patch 8.2.1348: build failure without the eval feature

Problem:    Build failure without the eval feature.
Solution:   Add #ifdef.
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 1f36bf7..185fc49 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -8581,7 +8581,6 @@
 				 (long)(current_sctx.sc_lnum + SOURCING_LNUM));
 		result = strbuf;
 		break;
-#endif
 
 	case SPEC_SID:
 		if (current_sctx.sc_sid <= 0)
@@ -8592,6 +8591,7 @@
 		sprintf((char *)strbuf, "<SNR>%d_", current_sctx.sc_sid);
 		result = strbuf;
 		break;
+#endif
 
 #ifdef FEAT_CLIENTSERVER
 	case SPEC_CLIENT:	// Source of last submitted input