RFR: JDK-8143141: Bring in minor build changes from the jigsaw/jake forest

[Jonathan Gibbons]

On 11/18/2015 01:20 PM, Mandy Chung wrote:
>   526 JAVAC_FLAGS := -bootclasspath $(EMPTY_DIR) -extdirs \
>   527     $(EMPTY_DIR) -endorseddirs $(EMPTY_DIR) $($(MODULE)_ADD_JAVAC_FLAGS)
>   528

A stylistic suggestion would be to split lines so as to group option 
name and value on the same line.

-- Jon