all: switch to LLVM 8

commands.go

@@ -4,8 +4,8 @@ package main
 
 // commands used by the compilation process might have different file names on Linux than those used on macOS.
 var commands = map[string]string{
-	"ar":      "llvm-ar-7",
-	"clang":   "clang-7",
-	"ld.lld":  "ld.lld-7",
-	"wasm-ld": "wasm-ld-7",
+	"ar":      "llvm-ar-8",
+	"clang":   "clang-8",
+	"ld.lld":  "ld.lld-8",
+	"wasm-ld": "wasm-ld-8",
 }