Rebuild configure file.

To finish #1059 and fix #1057.

configure

@@ -600,6 +600,7 @@ target_cxxflags
 target_cflags
 cmodel
 gcc_checking
+musl_multilib_names
 newlib_multilib_names
 glibc_multilib_names
 multilib_flags
@@ -1322,8 +1323,8 @@ Optional Features:
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-linux          set linux as the default make target
                           [--disable-linux]
-  --enable-multilib       build both RV32 and RV64 runtime libraries (only RV64 for musl libc)
-                          [--disable-multilib]
+  --enable-multilib       build both RV32 and RV64 runtime libraries (only
+                          RV64 for musl libc) [--disable-multilib]
   --enable-gcc-checking   Enable gcc internal checking, it will make gcc very
                           slow, only enable it when developing gcc
                           [--disable-gcc-checking]
@@ -1339,7 +1340,7 @@ Optional Packages:
                           available options: 2.2, 20190608, 20191213
   --with-multilib-generator
                           Multi-libs configuration string, only supported for
-                          bare-metal/elf toolchaih, this option implied
+                          bare-metal/elf toolchain, this option implied
                           --enable-multilib
   --with-cmodel           Select the code model to use when building libc and
                           libgcc [--with-cmodel=medlow]
@@ -3398,6 +3399,14 @@ else
 
 fi
 
+if test "x$enable_multilib" != xno; then :
+  musl_multilib_names="rv64imac-lp64 rv64imafdc-lp64d"
+
+else
+  musl_multilib_names="$with_arch-$with_abi"
+
+fi
+
 # Check whether --enable-gcc-checking was given.
 if test "${enable_gcc_checking+set}" = set; then :
   enableval=$enable_gcc_checking;
@@ -4836,3 +4845,4 @@ if test -n "$ac_unrecognized_opts" && test "$enable_option_checking" != no; then
   { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: unrecognized options: $ac_unrecognized_opts" >&5
 $as_echo "$as_me: WARNING: unrecognized options: $ac_unrecognized_opts" >&2;}
 fi
+