Using $ORIGIN as RUNPATH for runtime link

When upgrading from GPDB5 to GPDB6, gpupgrade will need to be able to call
binaries from both major versions. Relying on LD_LIBRARY_PATH is not an option
because this can cause binaries to load libraries from the wrong version.
Instead, we need the libraries to have RPATH/RUNPATH set correctly. Since the
built binaries may be relocated we need to use a relative path.

This commit disables the rpath configure option (which would result in an
absolute path) and exports LD_RUN_PATH to use `$ORIGIN`.

For most ELF files a RUNPATH of `$ORIGIN/../lib` is correct. For pygresql
python module, the RUNPATH needs to be adjusted accordingly.
Authored-by: NShaoqi Bai <sbai@pivotal.io>

gpAux/Makefile

@@ -253,6 +253,12 @@ ifdef ADDON_DIR
 CONFIGFLAGS+=ADDON_DIR=$(ADDON_DIR)
 endif
 
+ifneq "$(findstring $(BLD_ARCH),rhel6 rhel7)" ""
+CONFIGFLAGS+= --disable-rpath
+CONFIGFLAGS+= LDFLAGS='-Wl,--enable-new-dtags -Wl,-rpath,\$$$$ORIGIN/../lib'
+CONFIGFLAGS+= LDFLAGS_SL='-Wl,--enable-new-dtags -Wl,-rpath,\$$$$ORIGIN/../lib'
+endif
+
 RECONFIG :
 	rm -f Debug/GNUmakefile
 	rm -f Release/GNUmakefile
@@ -334,7 +340,11 @@ BLD_GPDB_BUILDSET=$($(BLD_ARCH)_GPDB_BUILDSET)
 # set default build steps
 define BUILD_STEPS
 	@rm -rf $(INSTLOC)
-	cd $(BUILDDIR) && $(MAKE) $(PARALLEL_MAKE_OPTS) install
+	if [ "$(findstring $(BLD_ARCH),rhel6 rhel7)" = "" ]; then \
+	  cd $(BUILDDIR) && $(MAKE) $(PARALLEL_MAKE_OPTS) install; \
+	else \
+	  cd $(BUILDDIR) && PYGRESQL_LDFLAGS='-Wl,-rpath,\$$$$ORIGIN/../../../lib -Wl,--enable-new-dtags' $(MAKE) $(PARALLEL_MAKE_OPTS) install; \
+	fi \
 	#@$(MAKE) greenplum_path INSTLOC=$(INSTLOC)
 	#@$(MAKE) mgmtcopy INSTLOC=$(INSTLOC)
 	@$(MAKE) mkpgbouncer INSTLOC=$(INSTLOC) BUILDDIR=$(BUILDDIR)

gpMgmt/bin/Makefile

@@ -64,7 +64,7 @@ pygresql:
 	elif [ "$(BLD_ARCH)" = 'aix7_ppc_64' ]; then \
 	    cd $(PYLIB_SRC)/$(PYGRESQL_DIR) && DESTDIR="$(DESTDIR)" CC="$(CC)" python_64 setup.py build; \
 	else \
-	    cd $(PYLIB_SRC)/$(PYGRESQL_DIR) && DESTDIR="$(DESTDIR)" CC="$(CC)" python setup.py build; \
+	    cd $(PYLIB_SRC)/$(PYGRESQL_DIR) && DESTDIR="$(DESTDIR)" CC="$(CC)" LDFLAGS='$(LDFLAGS) $(PYGRESQL_LDFLAGS)' python setup.py build; \
 	fi
 	mkdir -p $(PYLIB_DIR)/pygresql
 	if [ `uname -s` = 'Darwin' ]; then \