[libc][bazel] Add BUILD rules for fma and fmaf functions. (llvm#159502)

This change adds the capability to build fma/fmaf with Bazel (fmal,
fmaf128 variants are not implemented yet), and run smoke tests.

BUILD rules for regular MPFR-based tests will be added later, since they
require support for building rand/srand as well, which is missing in
Bazel for now.

Author: vonosmas

utils/bazel/llvm-project-overlay/libc/BUILD.bazel

@@ -3834,7 +3834,19 @@ libc_math_function(name = "floorf128")
 
 libc_math_function(name = "floorf16")
 
-# TODO: Add fma, fmaf, fmal, fmaf128 functions.
+libc_math_function(
+    name = "fma",
+    additional_deps = [
+        ":__support_fputil_fma",
+    ],
+)
+
+libc_math_function(
+    name = "fmaf",
+    additional_deps = [
+        ":__support_fputil_fma",
+    ],
+)
 
 libc_math_function(
     name = "fmaf16",

utils/bazel/llvm-project-overlay/libc/test/src/math/smoke/BUILD.bazel

@@ -475,7 +475,15 @@ math_test(
     hdrs = ["FloorTest.h"],
 )
 
-# TODO: Add fma, fmaf, fmal, fmaf128 tests.
+math_test(
+    name = "fma",
+    hdrs = ["FmaTest.h"],
+)
+
+math_test(
+    name = "fmaf",
+    hdrs = ["FmaTest.h"],
+)
 
 # TODO: Reenable this test once it passes at Google.
 # math_test(