--- old/make/lib/LibCommon.gmk	2018-06-07 22:09:38.120229585 +0200
+++ new/make/lib/LibCommon.gmk	2018-06-07 22:09:37.836229587 +0200
@@ -25,9 +25,6 @@
 
 include JdkNativeCompilation.gmk
 
-# Hook to include the corresponding custom file, if present.
-$(eval $(call IncludeCustomExtension, lib/LibCommon.gmk))
-
 ################################################################################
 
 GLOBAL_VERSION_INFO_RESOURCE := $(TOPDIR)/src/java.base/windows/native/common/version.rc
@@ -67,16 +64,6 @@
 endif
 
 ################################################################################
-# Find the default set of src dirs for a native library.
-# Param 1 - module name
-# Param 2 - library name
-FindSrcDirsForLib += \
-  $(call uniq, $(wildcard \
-      $(TOPDIR)/src/$(strip $1)/$(OPENJDK_TARGET_OS)/native/lib$(strip $2) \
-      $(TOPDIR)/src/$(strip $1)/$(OPENJDK_TARGET_OS_TYPE)/native/lib$(strip $2) \
-      $(TOPDIR)/src/$(strip $1)/share/native/lib$(strip $2)))
-
-################################################################################
 # Find a library
 # Param 1 - module name
 # Param 2 - library name
@@ -94,10 +81,6 @@
     $(addprefix $(SUPPORT_OUTPUTDIR)/native/, \
         $(strip $1)$(strip $3)/$(LIBRARY_PREFIX)$(strip $2)$(STATIC_LIBRARY_SUFFIX))
 
-################################################################################
-# Define the header include flags needed to compile against it.
-LIBJAVA_HEADER_FLAGS := $(addprefix -I, $(call FindSrcDirsForLib, java.base, java))
-
 # Put the libraries here.
 INSTALL_LIBRARIES_HERE := $(call FindLibDirForModule, $(MODULE))