Upgrade to Rust 1.17.

- Remove some uses of 'static in const and static globals that are no
  longer needed.
- Use the new struct initialization shorthand.

lib/cretonne/meta/gen_encoding.py

@@ -451,7 +451,7 @@ def emit_recipe_names(isa, fmt):
     This is used for pretty-printing encodings.
     """
     with fmt.indented(
-            'static RECIPE_NAMES: [&\'static str; {}] = ['
+            'static RECIPE_NAMES: [&str; {}] = ['
             .format(len(isa.all_recipes)), '];'):
         for r in isa.all_recipes:
             fmt.line('"{}",'.format(r.name))

lib/cretonne/meta/gen_instr.py

@@ -470,7 +470,7 @@ def gen_format_constructor(iform, fmt):
         # Generate the instruction data.
         with fmt.indented(
                 'let data = InstructionData::{} {{'.format(iform.name), '};'):
-            fmt.line('opcode: opcode,')
+            fmt.line('opcode,')
             gen_member_inits(iform, fmt)
 
         fmt.line('self.build(data, ctrl_typevar)')
@@ -489,7 +489,7 @@ def gen_member_inits(iform, fmt):
 
     # Value operands.
     if iform.has_value_list:
-        fmt.line('args: args,')
+        fmt.line('args,')
     elif iform.num_value_operands == 1:
         fmt.line('arg: arg0,')
     elif iform.num_value_operands > 1:

lib/cretonne/meta/gen_settings.py

@@ -132,7 +132,7 @@ def gen_descriptors(sgrp, fmt):
                     raise AssertionError("Unknown setting kind")
 
     with fmt.indented(
-            'static ENUMERATORS: [&\'static str; {}] = ['
+            'static ENUMERATORS: [&str; {}] = ['
             .format(len(enums.table)),
             '];'):
         for txt in enums.table: