Update cmake files and wamr-test-suites to support collect code coverage (#1992)

Support collecting code coverage with wamr-test-suites script by using
lcov and genhtml tools, eg.:
  cd tests/wamr-test-suites
  ./test_wamr.sh -s spec -b -P -C

The default code coverage and html files are generated at:
  tests/wamr-test-suites/workspace/wamr.lcov
  tests/wamr-test-suites/workspace/wamr-lcov.zip

And update wamr-test-suites scripts to support testing GC spec cases to
avoid frequent synchronization conflicts between branch main and dev/gc.

tests/wamr-test-suites/spec-test-script/collect_coverage.sh

@@ -0,0 +1,80 @@
+#!/usr/bin/env bash
+
+#
+# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#
+
+readonly WORK_DIR=$PWD
+readonly WAMR_DIR=${WORK_DIR}/../../..
+readonly DST_COV_FILE=$1
+readonly SRC_COV_DIR=$2
+readonly SRC_TEMP_COV_FILE=wamr_temp.lcov
+readonly SRC_COV_FILE=wamr.lcov
+
+# get dest folder
+dir=$(dirname ${DST_COV_FILE})
+pushd ${dir} > /dev/null 2>&1
+readonly DST_COV_DIR=${PWD}
+popd > /dev/null 2>&1
+
+if [[ ! -d ${SRC_COV_DIR} ]]; then
+    echo "${SRC_COV_DIR} doesn't exist, ignore code coverage collection"
+    exit
+fi
+
+echo "Start to collect code coverage of ${SRC_COV_DIR} .."
+
+pushd ${SRC_COV_DIR} > /dev/null 2>&1
+
+# collect all code coverage data
+lcov -o ${SRC_TEMP_COV_FILE} -c -d . --rc lcov_branch_coverage=1
+# extract code coverage data of WAMR source files
+lcov -r ${SRC_TEMP_COV_FILE} -o ${SRC_TEMP_COV_FILE} \
+     -rc lcov_branch_coverage=1 \
+     "*/usr/*" "*/_deps/*" "*/deps/*" "*/tests/unit/*" \
+     "*/llvm/include/*" "*/include/llvm/*" "*/samples/*" \
+     "*/app-framework/*" "*/test-tools/*"
+
+if [[ -s ${SRC_TEMP_COV_FILE} ]]; then
+    if [[ -s ${DST_COV_FILE} ]]; then
+        # merge code coverage data
+        lcov --rc lcov_branch_coverage=1 \
+            --add-tracefile ${SRC_TEMP_COV_FILE} \
+            -a ${DST_COV_FILE} -o ${SRC_COV_FILE}
+        # backup the original lcov file
+        cp -a ${DST_COV_FILE} "${DST_COV_FILE}.orig"
+        # replace the lcov file
+        cp -a ${SRC_COV_FILE} ${DST_COV_FILE}
+    else
+        cp -a ${SRC_TEMP_COV_FILE} ${SRC_COV_FILE}
+        cp -a ${SRC_COV_FILE} ${DST_COV_FILE}
+    fi
+
+    # get ignored prefix path
+    dir=$(dirname ${WAMR_DIR}/../..)
+    pushd ${dir} > /dev/null 2>&1
+    prefix_full_path=${PWD}
+    popd > /dev/null 2>&1
+
+    # generate html output for merged code coverage data
+    rm -fr ${DST_COV_DIR}/wamr-lcov
+    genhtml -t "WAMR Code Coverage" \
+        --rc lcov_branch_coverage=1 --prefix=${prefix_full_path} \
+        -o ${DST_COV_DIR}/wamr-lcov \
+        ${DST_COV_FILE}
+
+    cd ${DST_COV_DIR}
+    rm -f wamr-lcov.zip
+    zip -r -q -o wamr-lcov.zip wamr-lcov
+    rm -fr wamr-lcov
+
+    echo "Code coverage file ${DST_COV_FILE} was generated or appended"
+    echo "Code coverage html ${DST_COV_DIR}/wamr-lcov.zip was generated"
+else
+    echo "generate code coverage html failed"
+fi
+
+echo ""
+
+popd > /dev/null 2>&1