[Misc] Add fastdebug workflow in JDK repo to check pull request

Summary: add fastdebug workflow in JDK repo to check pull request

Test Plan: workflow shipped with this PR

Reviewed-by: luchsh, yuleil

Issue: alibaba/dragonwell8#82

.github/workflows/check_pr.yml

@@ -101,6 +101,74 @@ jobs:
           #run: |
           #make test TEST="hotspot_tier1 jdk_tier1"
 
+  build_fastdebug_jdk:
+    runs-on: ubuntu-latest
+    container:
+      image: docker.io/dragonwelljdk/build_jdk:8u
+    steps:
+      - name: Check out alibaba/dragonwell8_hotspot
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_hotspot'
+          path: 'hotspot'
+      - name: Check out alibaba/dragonwell8_corba
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_corba'
+          path: 'corba'
+      - name: Check out alibaba/dragonwell8_langtools
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_langtools'
+          path: 'langtools'
+      - name: Check out alibaba/dragonwell8
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8'
+          path: 'dragonwell8'
+      - name: Check out alibaba/dragonwell8_jdk
+        uses: actions/checkout@v2
+        with:
+          path: 'jdk'
+      - name: Check out alibaba/dragonwell8_jaxws
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_jaxws'
+          path: 'jaxws'
+      - name: Check out alibaba/dragonwell8_jaxp
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_jaxp'
+          path: 'jaxp'
+      - name: Check out alibaba/dragonwell8_nashorn
+        uses: actions/checkout@v2
+        with:
+          repository: 'alibaba/dragonwell8_nashorn'
+          path: 'nashorn'
+
+      - name: Compile fastdebug mode
+        run: |
+          mv hotspot dragonwell8
+          mv jdk dragonwell8
+          mv langtools dragonwell8
+          mv corba dragonwell8
+          mv jaxp dragonwell8
+          mv jaxws dragonwell8
+          mv nashorn dragonwell8
+          cd dragonwell8
+          sh configure --with-debug-level=fastdebug --with-cacerts-file=${PWD}/common/security/cacerts --with-milestone=fcs --enable-unlimited-crypto
+          make LOG=trace images
+
+      - name: Sanity test
+        run: |
+          cd dragonwell8
+          TEST_JDK_HOME=build/linux-x86_64-normal-server-fastdebug/images/j2sdk-image
+          ${TEST_JDK_HOME}/bin/java -version
+
+          # - name: Tier1 test
+          #  run: |
+          #    make test TEST="hotspot_tier1 jdk_tier1"
+
   build_slowdebug_jdk:
     runs-on: ubuntu-latest
     container: