patch 8.0.1550: various small problems in source files

Problem:    Various small problems in source files.
Solution:   Fix the problems.
diff --git a/src/Makefile b/src/Makefile
index 5a134a6..1b13aa9 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -651,12 +651,16 @@
 
 # PROFILING - Uncomment the next two lines to do profiling with gcc and gprof.
 # Might not work with GUI or Perl.
-# For unknown reasons adding "-lc" fixes a linking problem with some versions
-# of GCC.  That's probably a bug in the "-pg" implementation.
 # After running Vim see the profile result with: gprof vim gmon.out | vim -
 # Need to recompile everything after changing this: "make clean" "make".
 #PROFILE_CFLAGS = -pg -g -DWE_ARE_PROFILING
 #PROFILE_LIBS = -pg
+
+# GCC 5 and later need the -no-pie argument.
+#PROFILE_LIBS = -pg -no-pie
+
+# For unknown reasons adding "-lc" fixes a linking problem with some versions
+# of GCC.  That's probably a bug in the "-pg" implementation.
 #PROFILE_LIBS = -pg -lc