build: Fix tasking compiler b_lto detection for overrides

Actually take an override into account, ie:
```meson
library(
  ...
  override_options : {'b_lto' : false},
)
```

1 files changed, 7 insertions, 1 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index a7dfc890c..7ebf3050d 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -2183,7 +2183,13 @@ class StaticLibrary(BuildTarget):
             else:
                 self.suffix = 'a'
                 if 'c' in self.compilers and self.compilers['c'].get_id() == 'tasking' and not self.prelink:
-                    if self.environment.coredata.optstore.get_value_for(OptionKey('b_lto'), self.subproject):
+                    key = OptionKey('b_lto', self.subproject, self.for_machine)
+                    try:
+                        v = self.environment.coredata.get_option_for_target(self, key)
+                    except KeyError:
+                        v = self.environment.coredata.optstore.get_value_for(key)
+                    assert isinstance(v, bool), 'for mypy'
+                    if v:
                         self.suffix = 'ma'
         self.filename = self.prefix + self.name + '.' + self.suffix
         self.outputs[0] = self.filename