add new builtin function `@tan`

The reason for having `@tan` is that we already have `@sin` and `@cos`
because some targets have machine code instructions for them, but in the
case that the implementation needs to go into compiler-rt, sin, cos, and
tan all share a common dependency which includes a table of data. To
avoid duplicating this table of data, we promote tan to become a builtin
alongside sin and cos.

ZIR: The tag enum is at capacity so this commit moves
`field_call_bind_named` to be `extended`. I measured this as one of
the least used tags in the zig codebase.

Fix libc math suffix for `f32` being wrong in both stage1 and stage2.
stage1: add missing libc prefix for float functions.

1 files changed, 8 insertions, 0 deletions

diff --git a/src/BuiltinFn.zig b/src/BuiltinFn.zig
index 3bf7224fab..04cad19354 100644
--- a/src/BuiltinFn.zig
+++ b/src/BuiltinFn.zig
@@ -89,6 +89,7 @@ pub const Tag = enum {
     sqrt,
     sin,
     cos,
+    tan,
     exp,
     exp2,
     log,
@@ -772,6 +773,13 @@ pub const list = list: {
             },
         },
         .{
+            "@tan",
+            .{
+                .tag = .tan,
+                .param_count = 1,
+            },
+        },
+        .{
             "@exp",
             .{
                 .tag = .exp,