move tinyc to a separate repo and allow installing external dependencency (eg tinyc) from koch / library code (#13850)

* remove tinyc
* installDeps
* update tinyc paths

tools/deps.nim

@@ -0,0 +1,22 @@
+import os, uri, strformat
+
+proc exec(cmd: string) =
+  echo "deps.cmd: " & cmd
+  let status = execShellCmd(cmd)
+  doAssert status == 0, cmd
+
+const commitHead* = "HEAD"
+
+proc cloneDependency*(destDirBase: string, url: string, commit = commitHead, appendRepoName = true) =
+  let destDirBase = destDirBase.absolutePath
+  let p = url.parseUri.path
+  let name = p.splitFile.name
+  var destDir = destDirBase
+  if appendRepoName: destDir = destDir / name
+  let destDir2 = destDir.quoteShell
+  if not dirExists(destDir):
+    # note: old code used `destDir / .git` but that wouldn't prevent git clone
+    # from failing
+    exec fmt"git clone -q {url} {destDir2}"
+  exec fmt"git -C {destDir2} fetch -q"
+  exec fmt"git -C {destDir2} checkout -q {commit}"