Libmozjs dll vs so size

Hi, I need to compile JS engine for both windows and linux. I am compiling it accrding to this docs:
https://firefox-source-docs.mozilla.org/js/build.html

I compile firefox doing steps 1 and 2 from building firefox dosumentation and I set there that I want to compile SpiderMonkey (option 5). Before I start ./mach build, I apply this configuration:

# Build only the JS shell
ac_add_options --enable-project=js

# Enable the debugging tools: Assertions, debug only code etc.
#ac_add_options --enable-debug

#ac_add_options --disable-debug

ac_add_options --enable-release

ac_add_options --disable-tests

# Enable optimizations as well so that the test suite runs much faster. If
# you are having trouble using a debugger, you should disable optimization.
#ac_add_options --enable-optimize

# Use a dedicated objdir for SpiderMonkey debug builds to avoid
# conflicting with Firefox build with default configuration.
mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/obj-release-@CONFIG_GUESS@

After compilation the DLL on windows has over 30 MB and SO on Linux over 300 MB. That is realy great difference in size. Is it normal or am I missing something?

Thanks

On linux, performing strip -s libmozjs-*.so will reduce the file size by removing the debug symbols.