[libc][aarch64] Enable a bunch of math functions.

Namely, these are the functions enabled: rint*, lrint*, llrint*, lround*,
llround*, nearbyint*. They were previously not enabled because they
required rounding mode and FP exception support. Now that rounding mode
and FP exception support is available for Aarch64, they can be enabled.

libc/config/linux/aarch64/entrypoints.txt

@@ -90,6 +90,18 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.ilogb
     libc.src.math.ilogbf
     libc.src.math.ilogbl
+    libc.src.math.llrint
+    libc.src.math.llrintf
+    libc.src.math.llrintl
+    libc.src.math.llround
+    libc.src.math.llroundf
+    libc.src.math.llroundl
+    libc.src.math.lrint
+    libc.src.math.lrintf
+    libc.src.math.lrintl
+    libc.src.math.lround
+    libc.src.math.lroundf
+    libc.src.math.lroundl
     libc.src.math.ldexp
     libc.src.math.ldexpf
     libc.src.math.ldexpl
@@ -99,6 +111,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.modf
     libc.src.math.modff
     libc.src.math.modfl
+    libc.src.math.nearbyint
+    libc.src.math.nearbyintf
+    libc.src.math.nearbyintl
     libc.src.math.nextafter
     libc.src.math.nextafterf
     libc.src.math.nextafterl
@@ -108,6 +123,9 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.remquof
     libc.src.math.remquo
     libc.src.math.remquol
+    libc.src.math.rint
+    libc.src.math.rintf
+    libc.src.math.rintl
     libc.src.math.round
     libc.src.math.roundf
     libc.src.math.roundl