Simplify WASM2JS setup code. NFC (#23968)

Author: sbc100

tools/link.py

@@ -799,17 +799,17 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
     # to js.
     settings.WASM = 1
     settings.WASM2JS = 1
-    # Wasm bigint doesn't make sense with wasm2js, since it controls how the
-    # wasm and JS interact.
-    if user_settings.get('WASM_BIGINT') and settings.WASM_BIGINT:
-      exit_with_error('WASM_BIGINT=1 is not compatible with WASM=0 (wasm2js)')
-    settings.WASM_BIGINT = 0
-    feature_matrix.disable_feature(feature_matrix.Feature.JS_BIGINT_INTEGRATION)
+
   if settings.WASM == 2:
     # Requesting both Wasm and Wasm2JS support
     settings.WASM2JS = 1
+
+  if settings.WASM2JS:
+    settings.MAYBE_WASM2JS = 1
+    # Wasm bigint doesn't make sense with wasm2js, since it controls how the
+    # wasm and JS interact.
     if user_settings.get('WASM_BIGINT') and settings.WASM_BIGINT:
-      exit_with_error('WASM_BIGINT=1 is not compatible with WASM=2 (wasm2js)')
+      exit_with_error('WASM_BIGINT=1 is not compatible with wasm2js')
     settings.WASM_BIGINT = 0
     feature_matrix.disable_feature(feature_matrix.Feature.JS_BIGINT_INTEGRATION)
 
@@ -1524,9 +1524,6 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
   if options.use_closure_compiler == 2 and not settings.WASM2JS:
     exit_with_error('closure compiler mode 2 assumes the code is asm.js, so not meaningful for wasm')
 
-  if settings.WASM2JS:
-    settings.MAYBE_WASM2JS = 1
-
   if settings.AUTODEBUG:
     settings.REQUIRED_EXPORTS += ['_emscripten_tempret_set']