Add gcc-4.8 build job.

.github/workflows/c-cpp.yml

@@ -4,6 +4,32 @@ on: [push, pull_request]
 
 jobs:
 
+  # compile with older gcc4.8
+  build-gcc48:
+
+    runs-on: ubuntu-18.04
+    name: Build with gcc 4.8
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+
+      - name: Build
+        run: |
+            sudo apt-get update
+            sudo apt-get install -y build-essential
+            sudo apt-get install -y gcc-4.8 g++-4.8
+            g++-4.8 -std=c++11 -o loader_example loader_example.cc
+
+      - name: NoexceptBuild
+        run: |
+            g++-4.8 -DTINYGLTF_NOEXCEPTION -std=c++11 -o loader_example loader_example.cc
+
+      - name: RapidjsonBuild
+        run: |
+            git clone https://github.com/Tencent/rapidjson
+            g++-4.8 -DTINYGLTF_USE_RAPIDJSON -I./rapidjson/include/rapidjson -std=c++11 -o loader_example loader_example.cc
+
   build-linux:
 
     runs-on: ubuntu-latest