Name mangling in MASM (ML64) is inconsistent - masm

Question

With the following file and using the Microsoft assembler ML64 (v14.00.2410.0, that ships with VS 2015), the assembler is mangling the name of the first routine (asm_cli) by adding an underscore, but it doesn't mangle the name of the second routine (asm_diable_vm). Why? The listing file doesn't show the name mangling, but LINK/DUMP on the .OBJ file shows the addition of the underscore.
Partial output from LINK/DUMP
RELOCATIONS #3
Symbol Symbol
Offset Type Applied To Index Name
-------- ---------------- ----------------- -------- ------
00000070 SECREL 00000000 C $$000000
00000074 SECTION 0000 C $$000000
00000225 SECREL 00000000 A _asm_cli
00000229 SECTION 0000 A _asm_cli
00000259 SECREL 00000000 B asm_disable_vm
0000025D SECTION 0000 B asm_disable_vm
COFF SYMBOL TABLE
000 01035E92 ABS notype Static | #comp.id
001 00000010 ABS notype Static | #feat.00
002 00000000 SECT1 notype Static | .text$mn
Section length 25, #relocs 0, #linenums 0, checksum 0
004 00000000 SECT2 notype Static | .data
Section length 0, #relocs 0, #linenums 0, checksum 0
006 00000000 SECT3 notype Static | .debug$S
Section length 274, #relocs 6, #linenums 0, checksum 0
008 00000000 SECT4 notype Static | .debug$T
Section length 34, #relocs 0, #linenums 0, checksum 0
00A 00000000 SECT1 notype () External | _asm_cli
00B 00000010 SECT1 notype () External | asm_disable_vm
00C 00000000 SECT1 notype Static | $$000000
Assembly.asm
cr0_pg EQU 80000000h ; Paging bit. If set, enables paging (and uses CR3 as pointer to page tables)
cr4_pae EQU 20H ; Physical Address Extension. If set, uses extended page table size
;
; Declare an C-callable entry point
;
routine_start MACRO Name, Section
Section SEGMENT PARA 'CODE'
DB 6 DUP (0ccH) ; Padding required by the calling standard
ALIGN 16
PUBLIC Name
Name PROC FRAME
.ENDPROLOG
ENDM
;
; Declare the end of a routine
;
routine_end MACRO Name, Section
Name ENDP
Section ENDS
ENDM
routine_start asm_cli, _TEXT
CLI ; Disable interrupts
RET
routine_end asm_cli, _TEXT
routine_start asm_disable_vm, _TEXT
;
; Disable paging
;
MOV RAX, CR0 ; Get the contents of control register 0
AND EAX, 7fffffffH ; Clear the paging bit
MOV CR0, RAX ; Save back to the register
;
; Empty the Translation Look-aside Buffer (TLB) by clearing the address of the
; first-level page table
;
XOR RAX, RAX ; Clear EAX
MOV CR3, RAX ; Clear Control Register 3
;
; Disable Physical Address Extension (PAE)
;
MOV RAX, CR4 ; Get the contents of control register 4
AND AL, NOT cr4_pae ; Clear the PAE bit
MOV CR4, RAX ; Save back to the register
RET
routine_end asm_disable_vm, _TEXT
END