Update ensureTotalCapacity to ensureTotalCapacityPrecise where it makes sense

These calls are all late-initialization of ArrayList's that were initialized outside the current scope. This allows us to still get the potential memory-saving benefits of the 'precision' of initCapacity.

lib/std/coff.zig

@@ -276,7 +276,7 @@ pub const Coff = struct {
         if (self.sections.items.len == self.coff_header.number_of_sections)
             return;
 
-        try self.sections.ensureTotalCapacity(self.coff_header.number_of_sections);
+        try self.sections.ensureTotalCapacityPrecise(self.coff_header.number_of_sections);
 
         const in = self.in_file.reader();
 
@@ -297,7 +297,7 @@ pub const Coff = struct {
                 std.mem.set(u8, name[8..], 0);
             }
 
-            try self.sections.append(Section{
+            self.sections.appendAssumeCapacity(Section{
                 .header = SectionHeader{
                     .name = name,
                     .misc = SectionHeader.Misc{ .virtual_size = try in.readIntLittle(u32) },

src/Module.zig

@@ -4146,7 +4146,7 @@ pub fn analyzeFnBody(mod: *Module, decl: *Decl, func: *Fn, arena: *Allocator) Se
     // for the runtime ones.
     const fn_ty = decl.ty;
     const runtime_params_len = @intCast(u32, fn_ty.fnParamLen());
-    try inner_block.instructions.ensureTotalCapacity(gpa, runtime_params_len);
+    try inner_block.instructions.ensureTotalCapacityPrecise(gpa, runtime_params_len);
     try sema.air_instructions.ensureUnusedCapacity(gpa, fn_info.total_params_len * 2); // * 2 for the `addType`
     try sema.inst_map.ensureUnusedCapacity(gpa, fn_info.total_params_len);
 

src/link/MachO/CodeSignature.zig

@@ -102,7 +102,7 @@ pub fn calcAdhocSignature(
     var buffer = try allocator.alloc(u8, page_size);
     defer allocator.free(buffer);
 
-    try cdir.data.ensureTotalCapacity(allocator, total_pages * hash_size + id.len + 1);
+    try cdir.data.ensureTotalCapacityPrecise(allocator, total_pages * hash_size + id.len + 1);
 
     // 1. Save the identifier and update offsets
     cdir.inner.identOffset = cdir.inner.length;

src/link/MachO/commands.zig

@@ -223,7 +223,7 @@ pub const SegmentCommand = struct {
         var segment = SegmentCommand{
             .inner = inner,
         };
-        try segment.sections.ensureTotalCapacity(alloc, inner.nsects);
+        try segment.sections.ensureTotalCapacityPrecise(alloc, inner.nsects);
 
         var i: usize = 0;
         while (i < inner.nsects) : (i += 1) {