Add libm and libm-macros to the workspace

These should build and test correctly. `libm-test` and others that
depend on it are excluded since the necessary CI is not yet set up.

Author: tgross35

Cargo.toml

@@ -7,15 +7,45 @@ members = [
     "builtins-test",
     "builtins-test-intrinsics",
     "compiler-builtins",
+    "crates/libm-macros",
+    "libm",
+    # FIXME(libm): disabled until tests work in CI
+    # "libm-test",
+    # "crates/musl-math-sys",
+    # "crates/util",
 ]
 
 default-members = [
-    "compiler-builtins",
     "builtins-test",
+    "compiler-builtins",
+    "crates/libm-macros",
+    # FIXME(libm): disabled until tests work in CI
+    # "crates/libm-test"
+    "libm",
 ]
 
 [profile.release]
-panic = 'abort'
+panic = "abort"
 
 [profile.dev]
-panic = 'abort'
+panic = "abort"
+
+# FIXME(libm): these profiles are needed for testing
+# # The default release profile is unchanged.
+
+# # Release mode with debug assertions
+# [profile.release-checked]
+# inherits = "release"
+# debug-assertions = true
+# overflow-checks = true
+
+# # Release with maximum optimizations, which is very slow to build. This is also
+# # what is needed to check `no-panic`.
+# [profile.release-opt]
+# inherits = "release"
+# codegen-units = 1
+# lto = "fat"
+
+# [profile.bench]
+# # Required for iai-callgrind
+# debug = true