Converts all try! macros to ? syntax.

Fixes #46

lib/cretonne/src/ir/funcname.rs

@@ -42,9 +42,9 @@ fn needs_quotes(name: &str) -> bool {
 impl fmt::Display for FunctionName {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         if needs_quotes(&self.0) {
-            try!(f.write_char('"'));
+            f.write_char('"')?;
             for c in self.0.chars().flat_map(char::escape_default) {
-                try!(f.write_char(c));
+                f.write_char(c)?;
             }
             f.write_char('"')
         } else {

lib/cretonne/src/ir/immediates.rs

@@ -49,10 +49,10 @@ impl Display for Imm64 {
             //   0xffff_ffff_fff8_4400
             //
             let mut pos = (64 - x.leading_zeros() - 1) & 0xf0;
-            try!(write!(f, "0x{:04x}", (x >> pos) & 0xffff));
+            write!(f, "0x{:04x}", (x >> pos) & 0xffff)?;
             while pos > 0 {
                 pos -= 16;
-                try!(write!(f, "_{:04x}", (x >> pos) & 0xffff));
+                write!(f, "_{:04x}", (x >> pos) & 0xffff)?;
             }
             Ok(())
         }
@@ -178,7 +178,7 @@ fn format_float(bits: u64, w: u8, t: u8, f: &mut Formatter) -> fmt::Result {
 
     // All formats share the leading sign.
     if sign_bit != 0 {
-        try!(write!(f, "-"));
+        write!(f, "-")?;
     }
 
     if e_bits == 0 {

lib/cretonne/src/ir/instructions.rs

@@ -265,9 +265,9 @@ impl Display for VariableArgs {
     fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
         for (i, val) in self.0.iter().enumerate() {
             if i == 0 {
-                try!(write!(fmt, "{}", val));
+                write!(fmt, "{}", val)?;
             } else {
-                try!(write!(fmt, ", {}", val));
+                write!(fmt, ", {}", val)?;
             }
         }
         Ok(())
@@ -289,9 +289,9 @@ pub struct UnaryImmVectorData {
 
 impl Display for UnaryImmVectorData {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        try!(write!(f, "#"));
+        write!(f, "#")?;
         for b in &self.imm {
-            try!(write!(f, "{:02x}", b));
+            write!(f, "{:02x}", b)?;
         }
         Ok(())
     }
@@ -356,9 +356,9 @@ impl BranchData {
 
 impl Display for BranchData {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        try!(write!(f, "{}, {}", self.arg, self.destination));
+        write!(f, "{}, {}", self.arg, self.destination)?;
         if !self.varargs.is_empty() {
-            try!(write!(f, "({})", self.varargs));
+            write!(f, "({})", self.varargs)?;
         }
         Ok(())
     }

lib/cretonne/src/ir/jumptable.rs

@@ -97,14 +97,14 @@ impl<'a> Iterator for Entries<'a> {
 impl Display for JumpTableData {
     fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
         match self.table.first().and_then(|e| e.expand()) {
-            None => try!(write!(fmt, "jump_table 0")),
-            Some(first) => try!(write!(fmt, "jump_table {}", first)),
+            None => write!(fmt, "jump_table 0")?,
+            Some(first) => write!(fmt, "jump_table {}", first)?,
         }
 
         for dest in self.table.iter().skip(1).map(|e| e.expand()) {
             match dest {
-                None => try!(write!(fmt, ", 0")),
-                Some(ebb) => try!(write!(fmt, ", {}", ebb)),
+                None => write!(fmt, ", 0")?,
+                Some(ebb) => write!(fmt, ", {}", ebb)?,
             }
         }
         Ok(())