Ignore -fPIC flag when not building relocatable code

This issue was supposed to have been fixed in lld but it seems that
issues remain.  See https://reviews.llvm.org/D65922.

Fixes: #9690, #9013

Author: sbc100

emcc.py

@@ -1883,6 +1883,9 @@ def is_link_flag(flag):
         return any(flag.startswith(x) for x in ('-l', '-L', '-Wl,'))
 
       compile_args = [a for a in newargs if a and not is_link_flag(a)]
+      if '-fPIC' in compile_args and not shared.Settings.RELOCATABLE:
+        shared.warning('Ignoring -fPIC flag when not building with SIDE_MODULE or MAIN_MODULE')
+        compile_args.remove('-fPIC')
 
       # Bitcode args generation code
       def get_clang_command(input_files):

tests/test_core.py

@@ -8276,6 +8276,11 @@ def test_undefined_main(self):
     '''
     self.build(src, self.get_dir(), 'test.c')
 
+  def test_fpic_static(self):
+    self.emcc_args.append('-fPIC')
+    self.emcc_args.remove('-Werror')
+    self.do_run_in_out_file_test('tests', 'core', 'test_hello_world')
+
 
 # Generate tests for everything
 def make_run(name, emcc_args, settings=None, env=None):