meson: improve -ffinite-math-only option detection and silence warning when build with -Ofast (#37638)

meson.build

@@ -442,8 +442,16 @@ possible_common_link_flags = [
 c_args = get_option('c_args')
 
 # Our json library does not support -ffinite-math-only, which is enabled by -Ofast or -ffast-math.
-if (('-Ofast' in c_args or '-ffast-math' in c_args or '-ffinite-math-only' in c_args) and '-fno-finite-math-only' not in c_args)
-        error('-Ofast, -ffast-math, or -ffinite-math-only is specified in c_args.')
+have = false
+foreach arg : c_args
+        if arg in ['-ffinite-math-only', '-ffast-math', '-Ofast']
+                have = true
+        elif arg in ['-fno-finite-math-only', '-fno-fast-math']
+                have = false
+        endif
+endforeach
+if have
+        error('-ffinite-math-only is enabled (may be implied by -ffast-math or -Ofast) in c_args.')
 endif
 
 # Disable -Wmaybe-uninitialized when compiling with -Os/-O1/-O3/etc. There are
@@ -455,7 +463,8 @@ if cc.get_id() == 'gcc' and (not '02'.contains(get_option('optimization')) or
                              '-Os' in c_args or
                              '-O1' in c_args or
                              '-O3' in c_args or
-                             '-Og' in c_args)
+                             '-Og' in c_args or
+                             '-Ofast' in c_args)
         possible_common_cc_flags += '-Wno-maybe-uninitialized'
 endif