Second attempt:

Massive check in. This changes the "-fast" flag to "-O#" in llc. If you want to
use the old behavior, the flag is -O0. This change allows for finer-grained
control over which optimizations are run at different -O levels.

Most of this work was pretty mechanical. The majority of the fixes came from
verifying that a "fast" variable wasn't used anymore. The JIT still uses a
"Fast" flag. I'll change the JIT with a follow-up patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70343 91177308-0d34-0410-b5e6-96231b3b80d8

docs/CommandGuide/llc.pod

@@ -41,6 +41,12 @@ Other B<llc> options are as follows:
 
 Print a summary of command line options.
 
+=item B<-O>=I<uint>
+
+Generate code at different optimization levels. These correspond to the I<-O0>,
+I<-O1>, I<-O2>, I<-O3>, and I<-O4> optimization levels used by B<llvm-gcc> and
+B<clang>.
+
 =item B<-f>
 
 Overwrite output files. By default, B<llc> will refuse to overwrite