Bug 1677726 - Disable LTO for SmokeDMD.cpp r=andi

Sheriff note: We should keep this regardless of whether bug 1675600 sticks.

The comment above SmokeDMD's `RunTests()` says "This test relies on the compiler not doing various optimizations ... So we compile it with -O0 (or equivalent)".

That suggests that LTO should also be disallowed.

Differential Revision: https://phabricator.services.mozilla.com/D97336

memory/replace/dmd/test/moz.build

@@ -13,9 +13,9 @@ GeckoSimplePrograms(
 
 # See the comment at the top of SmokeDMD.cpp:RunTests().
 if CONFIG["CXX_TYPE"] == "clang-cl":
-    CXXFLAGS += ["-Og-"]
+    CXXFLAGS += ["-Og-", "-clang:-fno-lto"]
 else:
-    CXXFLAGS += ["-O0"]
+    CXXFLAGS += ["-O0", "-fno-lto"]
 
 DEFINES["MOZ_NO_MOZALLOC"] = True