Test moves, items, and abilities in battle

Thank you to SBird for providing mgba-rom-test binaries and Spikes/Toxic
Spikes tests!

Co-authored-by: sbird <sbird@no.tld>

.github/workflows/build.yml

@@ -29,7 +29,7 @@ jobs:
           repository: pret/agbcc
 
       - name: Install binutils
-        run: sudo apt install gcc-arm-none-eabi binutils-arm-none-eabi
+        run: sudo apt install gcc-arm-none-eabi binutils-arm-none-eabi libelf-dev
         # build-essential, git, and libpng-dev are already installed
         # gcc-arm-none-eabi is only needed for the modern build
         # as an alternative to dkP
@@ -41,10 +41,15 @@ jobs:
         working-directory: agbcc
 
       - name: Agbcc
-        run: make -j${nproc} all
+        run: make -j${nproc} -O all
 
       - name: Modern
         env:
           MODERN: 1
           COMPARE: 0
-        run: make -j${nproc} all
+        run: make -j${nproc} -O all
+
+      - name: Test
+        run: |
+          make -j${nproc} -O pokeemerald-test.elf
+          make -j${nproc} check