[libc] Update supported riscv libs

This patch updates the list of supported libs according to the latest changes to x86_64

Reviewed By: sivachandra

Differential Revision: https://reviews.llvm.org/D147961

Author: mikhailramalho

libc/config/linux/riscv64/entrypoints.txt

@@ -118,6 +118,8 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.stdio.remove
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
+    libc.src.stdio.fprintf
+    libc.src.stdio.printf
 
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
@@ -200,6 +202,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     libc.src.unistd.unlink
     libc.src.unistd.unlinkat
     libc.src.unistd.write
+
+    # wchar.h entrypoints
+    libc.src.wchar.wctob
 )
 
 set(TARGET_LIBM_ENTRYPOINTS
@@ -275,6 +280,7 @@ set(TARGET_LIBM_ENTRYPOINTS
     libc.src.math.llround
     libc.src.math.llroundf
     libc.src.math.llroundl
+    libc.src.math.log10
     libc.src.math.log10f
     libc.src.math.log1pf
     libc.src.math.log2f
@@ -406,7 +412,6 @@ if(LLVM_LIBC_FULL_BUILD)
     libc.src.stdio.funlockfile
     libc.src.stdio.fwrite
     libc.src.stdio.fwrite_unlocked
-    libc.src.stdio.fprintf
     libc.src.stdio.getc
     libc.src.stdio.getc_unlocked
     libc.src.stdio.getchar

libc/config/linux/riscv64/headers.txt

@@ -19,6 +19,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.threads
     libc.include.time
     libc.include.unistd
+    libc.include.wchar
 
     libc.include.arpa_inet