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, 15 insertions, 1 deletions

diff --git a/doc/langref.html.in b/doc/langref.html.in
index 5cccced446..3c5de6c8d2 100644
--- a/doc/langref.html.in
+++ b/doc/langref.html.in
@@ -8026,7 +8026,7 @@ fn func(y: *i32) void {
       only rounds once, and is thus more accurate.
       </p>
       <p>
-      Supports Floats and Vectors of floats.
+      Supports {#link|Floats#} and {#link|Vectors#} of floats.
       </p>
       {#header_close#}
 
@@ -9440,6 +9440,7 @@ fn doTheTest() !void {
       <a href="https://github.com/ziglang/zig/issues/4026">some float operations are not yet implemented for all float types</a>.
       </p>
       {#header_close#}
+
       {#header_open|@cos#}
       <pre>{#syntax#}@cos(value: anytype) @TypeOf(value){#endsyntax#}</pre>
       <p>
@@ -9451,6 +9452,19 @@ fn doTheTest() !void {
       <a href="https://github.com/ziglang/zig/issues/4026">some float operations are not yet implemented for all float types</a>.
       </p>
       {#header_close#}
+
+      {#header_open|@tan#}
+      <pre>{#syntax#}@tan(value: anytype) @TypeOf(value){#endsyntax#}</pre>
+      <p>
+      Tangent trigonometric function on a floating point number.
+      Uses a dedicated hardware instruction when available.
+      </p>
+      <p>
+      Supports {#link|Floats#} and {#link|Vectors#} of floats, with the caveat that
+      <a href="https://github.com/ziglang/zig/issues/4026">some float operations are not yet implemented for all float types</a>.
+      </p>
+      {#header_close#}
+
       {#header_open|@exp#}
       <pre>{#syntax#}@exp(value: anytype) @TypeOf(value){#endsyntax#}</pre>
       <p>