Place all release script temp files into a common workdir

This makes it easier to restart an aborted merge.

R=machenbach@chromium.org
TEST=ran tools/release/script_test.py locally

Bug: v8:7410
Change-Id: I26b1b09e0000c9c689ad80be32ced9e35634bcec
Reviewed-on: https://chromium-review.googlesource.com/905665
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51143}

tools/release/common_includes.py

@@ -51,6 +51,7 @@ PUSH_MSG_GIT_RE = re.compile(r".* \(based on (?P<git_rev>[a-fA-F0-9]+)\)$")
 PUSH_MSG_NEW_RE = re.compile(r"^Version \d+\.\d+\.\d+$")
 VERSION_FILE = os.path.join("include", "v8-version.h")
 WATCHLISTS_FILE = "WATCHLISTS"
+RELEASE_WORKDIR = "/tmp/v8-release-scripts-work-dir/"
 
 # V8 base directory.
 V8_BASE = os.path.dirname(

tools/release/merge_to_branch.py

@@ -241,11 +241,12 @@ class MergeToBranch(ScriptsBase):
   def _Config(self):
     return {
       "BRANCHNAME": "prepare-merge",
-      "PERSISTFILE_BASENAME": "/tmp/v8-merge-to-branch-tempfile",
+      "PERSISTFILE_BASENAME": RELEASE_WORKDIR + "v8-merge-to-branch-tempfile",
       "ALREADY_MERGING_SENTINEL_FILE":
-          "/tmp/v8-merge-to-branch-tempfile-already-merging",
-      "TEMPORARY_PATCH_FILE": "/tmp/v8-prepare-merge-tempfile-temporary-patch",
-      "COMMITMSG_FILE": "/tmp/v8-prepare-merge-tempfile-commitmsg",
+          RELEASE_WORKDIR + "v8-merge-to-branch-tempfile-already-merging",
+      "TEMPORARY_PATCH_FILE":
+          RELEASE_WORKDIR + "v8-prepare-merge-tempfile-temporary-patch",
+      "COMMITMSG_FILE": RELEASE_WORKDIR + "v8-prepare-merge-tempfile-commitmsg",
     }
 
   def _Steps(self):

tools/release/roll_merge.py

@@ -262,11 +262,13 @@ class RollMerge(ScriptsBase):
   def _Config(self):
     return {
       "BRANCHNAME": "prepare-merge",
-      "PERSISTFILE_BASENAME": "/tmp/v8-merge-to-branch-tempfile",
+      "PERSISTFILE_BASENAME":
+          RELEASE_WORKDIR + "v8-merge-to-branch-tempfile",
       "ALREADY_MERGING_SENTINEL_FILE":
-          "/tmp/v8-merge-to-branch-tempfile-already-merging",
-      "TEMPORARY_PATCH_FILE": "/tmp/v8-prepare-merge-tempfile-temporary-patch",
-      "COMMITMSG_FILE": "/tmp/v8-prepare-merge-tempfile-commitmsg",
+          RELEASE_WORKDIR + "v8-merge-to-branch-tempfile-already-merging",
+      "TEMPORARY_PATCH_FILE":
+          RELEASE_WORKDIR + "v8-prepare-merge-tempfile-temporary-patch",
+      "COMMITMSG_FILE": RELEASE_WORKDIR + "v8-prepare-merge-tempfile-commitmsg",
     }
 
   def _Steps(self):