Add a "colocated" flag to symbol references. (#298)

This adds a "colocated" flag to function and symbolic global variables which
indicates that they are defined along with the current function, so they can
use PC-relative addressing.

This also changes the function decl syntax; the name now always precedes the
signature, and the "function" keyword is no longer included.

cranelift/filetests/regalloc/basic.cton

@@ -53,7 +53,7 @@ ebb1(v10: i32):
 
 ; Pass an EBB argument as a function argument.
 function %callebb(i32, i32) -> i32 {
-    fn0 = function %foo(i32) -> i32
+    fn0 = %foo(i32) -> i32
 
 ebb0(v1: i32, v2: i32):
     brnz v1, ebb1(v1)
@@ -66,7 +66,7 @@ ebb1(v10: i32):
 
 ; Pass an EBB argument as a jump argument.
 function %jumpebb(i32, i32) -> i32 {
-    fn0 = function %foo(i32) -> i32
+    fn0 = %foo(i32) -> i32
 
 ebb0(v1: i32, v2: i32):
     brnz v1, ebb1(v1, v2)

cranelift/filetests/regalloc/coalescing-207.cton

@@ -11,9 +11,9 @@ function %pr207(i64 vmctx, i32, i32) -> i32 system_v {
     sig0 = (i64 vmctx, i32, i32) -> i32 system_v
     sig1 = (i64 vmctx, i32, i32, i32) -> i32 system_v
     sig2 = (i64 vmctx, i32, i32, i32) -> i32 system_v
-    fn0 = sig0 u0:2
-    fn1 = sig1 u0:0
-    fn2 = sig2 u0:1
+    fn0 = u0:2 sig0
+    fn1 = u0:0 sig1
+    fn2 = u0:1 sig2
 
 ebb0(v0: i64, v1: i32, v2: i32):
     v3 = iconst.i32 0
@@ -1038,7 +1038,7 @@ function %musl(f64 [%xmm0], i64 vmctx [%rdi]) -> f64 [%xmm0] system_v {
     gv0 = vmctx
     heap0 = static gv0, min 0, bound 0x0001_0000_0000, guard 0x8000_0000
     sig0 = (f64 [%xmm0], i32 [%rdi], i64 vmctx [%rsi]) -> f64 [%xmm0] system_v
-    fn0 = sig0 u0:517
+    fn0 = u0:517 sig0
 
 ebb0(v0: f64, v1: i64):
     v3 = iconst.i64 0

cranelift/filetests/regalloc/reload-208.cton

@@ -16,8 +16,8 @@ function %pr208(i64 vmctx [%rdi]) system_v {
     heap0 = static gv0, min 0, bound 0x5000, guard 0x0040_0000
     sig0 = (i64 vmctx [%rdi]) -> i32 [%rax] system_v
     sig1 = (i64 vmctx [%rdi], i32 [%rsi]) system_v
-    fn0 = sig0 u0:1
-    fn1 = sig1 u0:3
+    fn0 = u0:1 sig0
+    fn1 = u0:3 sig1
 
 ebb0(v0: i64):
     v1 = iconst.i32 0

cranelift/filetests/regalloc/reload.cton

@@ -5,7 +5,7 @@ isa riscv enable_e
 
 ; Check that we can handle a function return value that got spilled.
 function %spill_return() -> i32 {
-    fn0 = function %foo() -> i32 system_v
+    fn0 = %foo() -> i32 system_v
 
 ebb0:
     v0 = call fn0()

cranelift/filetests/regalloc/spill.cton

@@ -70,7 +70,7 @@ ebb0(v1: i32):
 
 ; All values live across a call must be spilled
 function %across_call(i32) {
-    fn0 = function %foo(i32)
+    fn0 = %foo(i32)
 ebb0(v1: i32):
     ; check: v1 = spill
     call fn0(v1)
@@ -83,7 +83,7 @@ ebb0(v1: i32):
 
 ; The same value used for two function arguments.
 function %doubleuse(i32) {
-    fn0 = function %xx(i32, i32)
+    fn0 = %xx(i32, i32)
 ebb0(v0: i32):
     ; check: $(c=$V) = copy v0
     call fn0(v0, v0)