all: remove libffi warning on macos

Running `go install` on MacOS produces the following warning:

    # github.com/tinygo-org/tinygo
    ld: warning: directory not found for option '-L/opt/homebrew/opt/libffi/lib'

It doesn't look like libffi is used anywhere, so I simply removed it.
Not sure why it was included in the first place.

(I updated the Makefile for consistency, but we really should be
removing that Makefile especially because the Go bindings are removed in
upstream LLVM).

go.mod

@@ -17,7 +17,7 @@ require (
 	golang.org/x/sys v0.0.0-20220829200755-d48e67d00261
 	golang.org/x/tools v0.1.11
 	gopkg.in/yaml.v2 v2.4.0
-	tinygo.org/x/go-llvm v0.0.0-20220922115213-dcb078a26266
+	tinygo.org/x/go-llvm v0.0.0-20221028183034-8341240c0b32
 )
 
 require (
@@ -29,5 +29,4 @@ require (
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-isatty v0.0.12 // indirect
-	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
 )

go.sum

@@ -47,7 +47,6 @@ github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5Cc
 go.bug.st/serial v1.3.5 h1:k50SqGZCnHZ2MiBQgzccXWG+kd/XpOs1jUljpDDKzaE=
 go.bug.st/serial v1.3.5/go.mod h1:z8CesKorE90Qr/oRSJiEuvzYRKol9r/anJZEb5kt304=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191008105621-543471e840be/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -64,5 +63,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
-tinygo.org/x/go-llvm v0.0.0-20220922115213-dcb078a26266 h1:vg4sYKEM+w6epr5S1nXqP/7UhMYcc8nRt7Ohkq28rok=
+tinygo.org/x/go-llvm v0.0.0-20221028183034-8341240c0b32 h1:LvdmoXncO43m2cws1chRB2hkLBAxfN6CbSjDI7+gk4Y=
-tinygo.org/x/go-llvm v0.0.0-20220922115213-dcb078a26266/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=
+tinygo.org/x/go-llvm v0.0.0-20221028183034-8341240c0b32/go.mod h1:GFbusT2VTA4I+l4j80b17KFK+6whv69Wtny5U+T8RR0=