[libc++] Reduce the number of warnings when running SPEC

Using -Wall and -Wextra when building SPEC leads to extremely large
log files. Since we don't actually care about warnings in these
benchmarks, this patches tones down the number of warnings a bit.

Author: ldionne

libcxx/test/benchmarks/spec.gen.py

@@ -28,6 +28,9 @@
 link_flags = (test_dir / 'link_flags.subs').open().read().strip()
 spec_dir = pathlib.Path((test_dir / 'spec_dir.subs').open().read().strip())
 
+# Remove -Wall, -Wextra and -Werror from the flags since we don't care about enabling all warnings inside SPEC
+compile_flags = compile_flags.replace('-Wall', '').replace('-Wextra', '').replace('-Werror', '')
+
 # Setup the configuration file
 test_dir.mkdir(parents=True, exist_ok=True)
 spec_config = test_dir / 'spec-config.cfg'
@@ -46,7 +49,7 @@
     copies               = 1
     threads              = 1
     CC                   = cc -O3
-    CXX                  = {cxx} {compile_flags} {flags} {link_flags} -Wno-error
+    CXX                  = {cxx} {compile_flags} {flags} {link_flags}
     CC_VERSION_OPTION    = --version
     CXX_VERSION_OPTION   = --version
     EXTRA_PORTABILITY    = -DSPEC_NO_CXX17_SPECIAL_MATH_FUNCTIONS # because libc++ doesn't implement the special math functions yet