add .o file writing for inline asm in llc. Here's a silly

demo:

$ clang asm.c -S -o - -emit-llvm | llc -filetype=obj -o t.o
<inline asm>:1:2: error: unrecognized instruction
	abc incl    %eax
	^
LLVM ERROR: Error parsing inline asm

Only problem seems to be that the parser finalizes OutStreamer 
at the end of the first inline asm, which isn't what we want.
For example:

$ cat asm.c
int foo(int X) {
 __asm__ ("incl    %0" : "+r" (X));
 return X;
}
$ clang asm.c -S -o - -emit-llvm | llc
...
	subq	$8, %rsp
	movl	%edi, (%rsp)
	movl	%edi, %eax
	## InlineAsm Start
	incl    %eax
	## InlineAsm End
	movl	%eax, (%rsp)
	movl	%eax, 4(%rsp)
	addq	$8, %rsp
	ret
$ clang asm.c -S -o - -emit-llvm | llc -filetype=obj -o t.o
$ otool -tv t.o
t.o:
(__TEXT,__text) section
_foo:
0000000000000000	subq	$0x08,%rsp
0000000000000004	movl	%edi,(%rsp)
0000000000000007	movl	%edi,%eax
0000000000000009	incl	%eax
$ 

don't stop at inc!

llvm-svn: 100491