patch 8.1.0598: indent tests may use the wrong Vim binary

Problem:    Indent tests may use the wrong Vim binary.
Solution:   Pass in the just built Vim binary.
diff --git a/Makefile b/Makefile
index 3e69d45..2155b58 100644
--- a/Makefile
+++ b/Makefile
@@ -39,10 +39,18 @@
 	@echo "Starting make in the src directory."
 	@echo "If there are problems, cd to the src directory and run make there"
 	cd src && $(MAKE) $@
+	# When the target is "test" also run the indent tests.
+	@if test "$@" = "test"; then \
+		$(MAKE) indenttest; \
+	fi
 
-test: all
-	cd src && $(MAKE) test
-	cd runtime/indent && $(MAKE) clean && $(MAKE) test
+# Executable used for running the indent tests.
+VIM_FOR_INDENTTEST = ../../src/vim
+
+indenttest:
+	cd runtime/indent && \
+		$(MAKE) clean VIM="$(VIM_FOR_INDENTTEST)" && \
+		$(MAKE) test VIM="$(VIM_FOR_INDENTTEST)"
 		
 
 #########################################################################
diff --git a/src/version.c b/src/version.c
index a85295a..7e8b34e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    598,
+/**/
     597,
 /**/
     596,