build: fix gocvr version used for coverage

Fix the gcovr version to a fixed version and uses patches
specific to that version. This avoids us being broken by
changes in the gcovr repo. Using file name for patches
specific to the version level will allow us to move up when
necessary without breaking coverage for earlier versions
of Node.js

PR-URL: nodejs#19094
Reviewed-By: Gibson Fahnestock <[email protected]>

Makefile

@@ -172,13 +172,13 @@ coverage-build: all
 		$(NODE) ./deps/npm install istanbul-merge --no-save --no-package-lock; fi
 	if [ ! -d node_modules/nyc ]; then \
 		$(NODE) ./deps/npm install nyc --no-save --no-package-lock; fi
-	if [ ! -d gcovr ]; then git clone --depth=1 \
+	if [ ! -d gcovr ]; then git clone -b 3.4 --depth=1 \
 		--single-branch git://github.com/gcovr/gcovr.git; fi
 	if [ ! -d build ]; then git clone --depth=1 \
 		--single-branch https://github.com/nodejs/build.git; fi
-	if [ ! -f gcovr/gcovr/gcov.py.orig ]; then \
-		(cd gcovr && patch -b -N -p1 < \
-		"$(CURDIR)/build/jenkins/scripts/coverage/gcovr-patches.diff"); fi
+	if [ ! -f gcovr/scripts/gcovr.orig ]; then \
+		(cd gcovr && patch -N -p1 < \
+		"$(CURDIR)/build/jenkins/scripts/coverage/gcovr-patches-3.4.diff"); fi
 	if [ -d lib_ ]; then $(RM) -r lib; mv lib_ lib; fi
 	mv lib lib_
 	$(NODE) ./node_modules/.bin/nyc instrument --extension .js --extension .mjs lib_/ lib/
@@ -203,7 +203,7 @@ coverage-test: coverage-build
 	(cd lib && .$(NODE) ../node_modules/.bin/nyc report \
 		--temp-directory "$(CURDIR)/.cov_tmp" \
 		--report-dir "../coverage")
-	-(cd out && PYTHONPATH=$(CURDIR)/gcovr $(PYTHON) -m gcovr --gcov-exclude='.*deps' \
+	-(cd out && "../gcovr/scripts/gcovr" --gcov-exclude='.*deps' \
 		--gcov-exclude='.*usr' -v -r Release/obj.target \
 		--html --html-detail -o ../coverage/cxxcoverage.html \
 		--gcov-executable="$(GCOV)")