Net alias not properly considered when creating set_{min,max}_delay constrainst

Issue from https://github.com/SymbiFlow/vtr-verilog-to-routing/issues/524. Alias are not considered when processing the get_clocks call when doing min/max delay constrainsts in the SDC.

Expected Behaviour

In the input netlist where you have theses aliases :

.names usb_I.uc_clk clk_wb
1 1
.names usb_I.tx_pkt_I.crc_16_I.clk clk_usb
1 1

Then the constraints :

set_max_delay 40 -from [get_clocks {clk_wb}] -to [get_clocks {clk_usb}]

and

set_max_delay 40 -from [get_clocks {usb_I.tx_pkt_I.crc_16_I.clk}] -to [get_clocks {usb_I.uc_clk}]

should be equivalent. But in reality, only the latter works because aliases are not considered.

Current Behaviour

The SDC parsing fails with set_max_path must specify at least one -from or -to clock because it doesn't find any clocks.

Possible Solution

Fix https://github.com/verilog-to-routing/vtr-verilog-to-routing/blob/master/vpr/src/timing/read_sdc.cpp#L896 to also process net aliases like it was done for create_clock.

Steps to Reproduce

Try to setup any max/min delay constrainst using the non-primary clock name from the EBLIF.

Context

I'd like to setup constrainst with a stable clock net name and not some random name that was randomly picked among all the possible aliases by the synthesis tool.

Your Environment

VTR revision used: 8980e46218542888fac879961b13aa7b0fba8432
Operating System and version: Linux
Compiler version: gcc 9.2.0

verilog-to-routing / vtr-verilog-to-routing