math: add empty __invtrigl.s to i386 and x86_64

__invtrigl is not needed when acosl, asinl, atanl have asm
implementations
diff --git a/src/math/i386/__invtrigl.s b/src/math/i386/__invtrigl.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/math/i386/__invtrigl.s
diff --git a/src/math/x86_64/__invtrigl.s b/src/math/x86_64/__invtrigl.s
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/math/x86_64/__invtrigl.s