Provide build_oai/cmake option to build with memory sanitizer

cmake_targets/build_oai

@@ -167,6 +167,10 @@ Options:
   Enable the address sanitizer on all targets
 --sanitize-undefined | -fsanitize=undefined
   Enable the undefined behavior sanitizer on all targets
+--sanitize-memory | -fsanitize=memory
+  Enable the memory sanitizer on all targets. Requires clang, and is
+  incompatible with ASan/UBSan. To build, issue:
+  CC=/usr/bin/clang CXX=/usr/bin/clang++ ./build_oai ... --sanitize-memory
 -h | --help
    Print this help"
 }
@@ -413,6 +417,11 @@ function main() {
         --sanitize-undefined | -fundefined=address)
             CMAKE_CMD="$CMAKE_CMD -DSANITIZE_UNDEFINED=True"
             shift;;
+        --sanitize-memory | -fsanitize=memory)
+            echo_warning "Note: memory sanitizer\n* requires clang (tested: v17)\n* is incompatible with address/undefined behavior sanitizer\n* requires cmake_targets/tools/memsan.patch"
+            sleep 5
+            CMAKE_CMD="$CMAKE_CMD -DSANITIZE_MEMORY=ON -DSANITIZE_ADDRESS=OFF -DSANITIZE_UNDEFINED=OFF"
+            shift;;
         -h | --help)
             print_help
             exit 1;;