Error if GLOBAL_BASE is used with relocatable output

These two options are not compatible, and `GLOBAL_BASE` is currently
just ignored in this mode.

Author: sbc100

test/test_other.py

@@ -1273,6 +1273,10 @@ def test_wl_stackfirst(self):
     err = self.expect_fail(cmd + ['-sGLOBAL_BASE=1024'])
     self.assertContained('error: --stack-first is not compatible with -sGLOBAL_BASE', err)
 
+  def test_dylink_global_base(self):
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-sGLOBAL_BASE=1024', '-sMAIN_MODULE'])
+    self.assertContained('emcc: error: GLOBAL_BASE is not compatible with relocatable output', err);
+
   @parameterized({
     # In a simple -O0 build we do not set --low-memory-unused (as the stack is
     # first, which is nice for debugging but bad for code size (larger globals)

tools/link.py

@@ -1049,6 +1049,8 @@ def phase_linker_setup(options, state, newargs):
         '__asyncify_data'
       ]
 
+    if 'GLOBAL_BASE' in user_settings:
+      exit_with_error('GLOBAL_BASE is not compatible with relocatable output')
     if settings.MINIMAL_RUNTIME:
       exit_with_error('MINIMAL_RUNTIME is not compatible with relocatable output')
     if settings.WASM2JS: