Bug 1867423 - Stop using -nopie. r=firefox-build-system-reviewers,sergesanspaille

Clang trunk removed its support in llvm/llvm-project#72578
and we were only using it because clang < 5 didn't support -no-pie. We
don't support those versions anymore, so we can use -no-pie
unconditionally now.

Differential Revision: https://phabricator.services.mozilla.com/D195061

Author: glandium

browser/app/no-pie/moz.build

@@ -17,8 +17,4 @@ CFLAGS += [
 
 # Use OS_LIBS instead of LDFLAGS to "force" the flag to come after -pie
 # from MOZ_PROGRAM_LDFLAGS.
-if CONFIG["CC_TYPE"] == "clang":
-    # clang < 5.0 doesn't support -no-pie.
-    OS_LIBS += ["-nopie"]
-else:
-    OS_LIBS += ["-no-pie"]
+OS_LIBS += ["-no-pie"]