compilers: remove hasattr from can_compile_suffixes

This is never set outside the `Compiler.__init__`, only added to. As
such there's no reason to have this `hasattr` check. It's wasting time
*and* confusing our static checkers.

mesonbuild/compilers/compilers.py

@@ -451,10 +451,8 @@ def __init__(self, ccache: T.List[str], exelist: T.List[str], version: str,
                  full_version: T.Optional[str] = None, is_cross: bool = False):
         self.exelist = ccache + exelist
         self.exelist_no_ccache = exelist
-        # In case it's been overridden by a child class already
         self.file_suffixes = lang_suffixes[self.language]
-        if not hasattr(self, 'can_compile_suffixes'):
-            self.can_compile_suffixes: T.Set[str] = set(self.file_suffixes)
+        self.can_compile_suffixes = set(self.file_suffixes)
         self.default_suffix = self.file_suffixes[0]
         self.version = version
         self.full_version = full_version

mesonbuild/compilers/mixins/ccrx.py

@@ -40,7 +40,6 @@ class CcrxCompiler(Compiler):
 
     if T.TYPE_CHECKING:
         is_cross = True
-        can_compile_suffixes: T.Set[str] = set()
 
     id = 'ccrx'