RFR: JDK-8244928 Build log output too verbose after JDK-8244844

[Magnus Ihse Bursie]

Unfortunately, an error crept into JDK-8244844 so that the build log 
displays the filenames of all compiled java files, instead of the count 
of files.

Bug: https://bugs.openjdk.java.net/browse/JDK-8244928
Patch inline:
diff --git a/make/common/JavaCompilation.gmk 
b/make/common/JavaCompilation.gmk
--- a/make/common/JavaCompilation.gmk
+++ b/make/common/JavaCompilation.gmk
@@ -428,7 +428,7 @@
      # list of files.
      $$($1_FILELIST): $$($1_SRCS) $$($1_VARDEPS_FILE)
                 $$(call MakeDir, $$(@D))
-               $$(call LogWarn, Compiling $$($1_SRCS) files for $1)
+               $$(call LogWarn, Compiling $$(words $$($1_SRCS)) files 
for $1)
                 $$(eval $$(call ListPathsSafely, $1_SRCS, $$($1_FILELIST)))

      # Do the actual compilation

/Magnus