sci-electronics/verilator: depend on app-arch/lz4 for FST tracing

Verilator FST waveform tracing links liblz4, seen in verilated.mk under
VM_TRACE_FST, but RDEPEND declared only zlib. On a clean image FST traced
models fail to link, breaking the verilator FST tests in sci-electronics/circt.

Closes: https://bugs.gentoo.org/978769
Signed-off-by: Huang Rui <vowstar@gmail.com>

sci-electronics/verilator/verilator-5.050-r1.ebuild

@@ -30,6 +30,7 @@ REQUIRED_USE="${PYTHON_REQUIRED_USE}"
 RDEPEND="
 	${PYTHON_DEPS}
 	dev-lang/perl
+	app-arch/lz4:=
 	virtual/zlib:=
 "
 

sci-electronics/verilator/verilator-9999.ebuild

@@ -30,6 +30,7 @@ REQUIRED_USE="${PYTHON_REQUIRED_USE}"
 RDEPEND="
 	${PYTHON_DEPS}
 	dev-lang/perl
+	app-arch/lz4:=
 	virtual/zlib:=
 "