Update build workflow to include core dump check

The change introduces gdb installation and enables core dumps in the GitHub Actions workflow for debugging failed builds. It also modifies the commands under the "run demo" section and adds a new step that checks for the presence of a core dump file whenever a test failure occurs.

.github/workflows/build.yml

@@ -24,7 +24,12 @@ jobs:
           extensions: mbstring, intl
 
       - name: Install build tools
-        run: sudo apt-get update && sudo apt-get install -y autoconf automake libtool bison re2c
+        run: sudo apt-get update && sudo apt-get install -y autoconf automake libtool bison re2c gdb
+
+      - name: Enable core dumps
+        run: |
+          ulimit -c unlimited
+          echo '/tmp/core.%e.%p' | sudo tee /proc/sys/kernel/core_pattern
 
       - name: Prepare build
         run: |
@@ -37,5 +42,17 @@ jobs:
 
       - name: Run demo
         run: |
-          php -d extension=./modules/rayaop.so -i | grep rayaop
-          timeout 60s php -d extension=./modules/rayaop.so -d memory_limit=128M -d report_memleaks=1 -d zend.assertions=1 -d assert.exception=1 rayaop.php
+          php -dextension=./modules/rayaop.so -i | grep rayaop
+          timeout 60s php -dextension=./modules/rayaop.so -dmemory_limit=128M -dreport_memleaks=1 -dzend.assertions=1 -dassert.exception=1 smoke.php
+
+      - name: Check for core dump
+        if: failure()
+        run: |
+          if ls /tmp/core.* 1> /dev/null 2>&1; then
+            for corefile in /tmp/core.*; do
+              echo "Core dump found: $corefile"
+              gdb -batch -ex "bt full" -ex "quit" -c $corefile $(which php)
+            done
+          else
+            echo "No core dump found"
+          fi