[WebAssembly] Reapply r252858, with svn add for the new file.

Switch to MC for instruction printing.

This encompasses several changes which are all interconnected:
 - Use the MC framework for printing almost all instructions.
 - AsmStrings are now live.
 - This introduces an indirection between LLVM vregs and WebAssembly registers,
   and a new pass, WebAssemblyRegNumbering, for computing a basic the mapping.
   This addresses some basic issues with argument registers and unused registers.
 - The way ARGUMENT instructions are handled no longer generates redundant
   get_local+set_local for every argument.

This also changes the assembly syntax somewhat; most notably, MC's printing
does not use sigils on label names, so those are no longer present, and
push/pop now have a sigil to keep them unambiguous.

The usage of set_local/get_local/$push/$pop will continue to evolve
significantly. This patch is just one step of a larger change.

llvm-svn: 252910
diff --git a/llvm/test/CodeGen/WebAssembly/store.ll b/llvm/test/CodeGen/WebAssembly/store.ll
index f89e837..206c31a 100644
--- a/llvm/test/CodeGen/WebAssembly/store.ll
+++ b/llvm/test/CodeGen/WebAssembly/store.ll
@@ -9,11 +9,7 @@
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .local i32, i32{{$}}
-; CHECK-NEXT: get_local push, 1{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: get_local push, 0{{$}}
-; CHECK-NEXT: set_local 3, pop{{$}}
-; CHECK-NEXT: i32.store (get_local 3), (get_local 2){{$}}
+; CHECK-NEXT: i32.store (get_local 0), (get_local 1){{$}}
 ; CHECK-NEXT: return{{$}}
 define void @sti32(i32 *%p, i32 %v) {
   store i32 %v, i32* %p
@@ -24,11 +20,7 @@
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .param i64{{$}}
 ; CHECK-NEXT: .local i64, i32{{$}}
-; CHECK-NEXT: get_local push, 1{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: get_local push, 0{{$}}
-; CHECK-NEXT: set_local 3, pop{{$}}
-; CHECK-NEXT: i64.store (get_local 3), (get_local 2){{$}}
+; CHECK-NEXT: i64.store (get_local 0), (get_local 1){{$}}
 ; CHECK-NEXT: return{{$}}
 define void @sti64(i64 *%p, i64 %v) {
   store i64 %v, i64* %p
@@ -39,11 +31,7 @@
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .param f32{{$}}
 ; CHECK-NEXT: .local f32, i32{{$}}
-; CHECK-NEXT: get_local push, 1{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: get_local push, 0{{$}}
-; CHECK-NEXT: set_local 3, pop{{$}}
-; CHECK-NEXT: f32.store (get_local 3), (get_local 2){{$}}
+; CHECK-NEXT: f32.store (get_local 0), (get_local 1){{$}}
 ; CHECK-NEXT: return{{$}}
 define void @stf32(float *%p, float %v) {
   store float %v, float* %p
@@ -54,11 +42,7 @@
 ; CHECK-NEXT: .param i32{{$}}
 ; CHECK-NEXT: .param f64{{$}}
 ; CHECK-NEXT: .local f64, i32{{$}}
-; CHECK-NEXT: get_local push, 1{{$}}
-; CHECK-NEXT: set_local 2, pop{{$}}
-; CHECK-NEXT: get_local push, 0{{$}}
-; CHECK-NEXT: set_local 3, pop{{$}}
-; CHECK-NEXT: f64.store (get_local 3), (get_local 2){{$}}
+; CHECK-NEXT: f64.store (get_local 0), (get_local 1){{$}}
 ; CHECK-NEXT: return{{$}}
 define void @stf64(double *%p, double %v) {
   store double %v, double* %p