refactored openroad stuff into OpenROADTool base class. fixed PR suggestions

vlsi/Makefile

@@ -38,7 +38,7 @@ HAMMER_EXEC        ?= $(if $(filter $(tech_name),nangate45),\
 VLSI_TOP           ?= $(TOP)
 VLSI_HARNESS_DUT_NAME ?= dut
 VLSI_OBJ_DIR       ?= $(vlsi_dir)/build
-ifneq ($(CUSTOM_VLOG), )
+ifneq ($(CUSTOM_VLOG),)
 	OBJ_DIR          ?= $(VLSI_OBJ_DIR)/custom-$(VLSI_TOP)
 else
 	OBJ_DIR          ?= $(VLSI_OBJ_DIR)/$(long_name)-$(VLSI_TOP)

vlsi/example-nangate45.yml

@@ -1,7 +1,8 @@
 # Technology Setup
-# Technology used is nanagate45
 vlsi.core.technology: nangate45
+
 # Specify dir with ASAP7 tarball
+# TODO: figure out how to remove this, or override it within OpenROADTool
 technology.nangate45.install_dir: "/k/work/OpenROAD-flow/tools/OpenROAD"
 
 vlsi.core.max_threads: 12